Imitrex

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Juhana Karha, MD

• Fellow, Cardiovascular Medicine
• Department of Cardiovascular Medicine
• Cleveland Clinic Foundation
• Cleveland, Ohio

Its chief meansofelimination may actually be the gradual and natural sloughing of amiodarone- packed epithelial cells spasms hands order imitrex australia. The half-life of the drug has been reported as being between2weeks and 3 months in duration spasms upper left abdomen cheap imitrex 100 mg on-line. This extraordi- narily long half-life is reectedinthe lowdaily dosage requirement after loading has been achieved infantile spasms youtube order discount imitrex online. By giving large doses for days to weeks spasms when i pee order imitrex 50mg, one can achieve relatively rapid saturation of the central and peripheral compartments. Achieving a steady state, however, requires lling the deepcompartment, which takes many weeks. When treating non-life-threatening arrhythmias or whenusing amiodaroneasprophylaxisagainst arrhythmias that are not mani- fest, a much gentler loading regimenis oftenused. Less aggressive loading schedules may avoid some toxicities associatedwith admin- istering higher doses of the drug but require signicantly more time to achieve both an antiarrhythmic effectand a steady state. The use of intravenousamiodarone is generally reserved for the treatmentofrecurrentlife-threatening ventricular tachyarrhyth- mias that have not responded to other therapies. Accordingly, the most prominent electrophysiologic effect is prolongation of the Table 5. Any immediate antiar- rhythmic efcacy with intravenousamiodarone islikely to be at least partially related to howdependentapatients arrhythmias are oncatecholaminestimulation. When amiodarone is loadedintravenously, 1 gis deliveredduring the rst 24 hours as follows: 150 mg is infusedduring the rst 10 minutes (15 mg/min), followed by 360 mg during the next 6 hours (1 mg/min), and then followed by 540 mg during the next 18 hours (0. If intravenous therapy isstill desired after the rst 24 hours, the infusioncancontinue at 0. Amiodarone is the most effective drug yet developed for recur- rentventricular brillation or hemodynamically unstable ventricu- lar tachycardia. Early studies with amiodarone generally limitedits use to patients whose ventricular tachyarrhythmias hadproven re- fractory (most often,asdocumentedduring electrophysiologic test- ing) to other antiarrhythmic therapy. Eveninthis difcult-to-treat population,amiodaronereduced the risk of suddendeath to about half that seenwith more conventional drugs. In subsequentrandom- ized trials, however, amiodarone proved to be signicantly inferior to the implantable debrillator in reducing mortality. The main in- dications for oral amiodaronetoday in the treatmentofventricular arrhythmias are to either reduce the frequencyofshocks in patients who have implantable debrillators or offer at least partially effective therapytopatients deemednot to be candidates for an implantable debrillator. Amiodarone is moderately effective in maintaining sinus rhythm in patients with atrial tachyarrhythmias, including atrial brillation and atrial utter. Inpatients with heart failure, amiodarone is prob- ably the drug of choice after cardioversion for atrial brillation,since it has few adverse hemodynamic effects, and often results in a well- controlled ventricular response should the arrhythmiarecur. Adverse effects and interactions Amiodarone causes a high incidenceofside effects, ranging from merely annoying to life threatening. Manyside effects of amiodarone appear to be related to the total lifetime cumulative dose of the drug (rather than to the daily dosage). Evenwhen lowdaily dosages are used, therefore, signicantside effects are seen,and the risk of de- veloping new side effects continues to increase as therapy continues over time. Side effects occur in approximately 15% of patients dur- ing the rst year but increase to over 50% with chronic therapy. Ad- verse effects require discontinuation of the drug in approximately 20% of patients. It has been widely speculated that much of the uniqueorgan toxicity seenwith amiodarone is related to the io- dine atoms containedinthe drug, a feature not shared by any other antiarrhythmic drug. Nausea, vomiting,oranorexia have an incidence of approximately 25% during the high-dose loading phase, but these symptoms often improve with lowering of the daily dosage. Esophageal reux caused by an amiodarone-inducedparalysis of the lower esophageal sphincter isan uncommon but potentially devas- tating side effect. Elevation of hepatic transaminases of up to twice normal values is seeninabout 25% of patients treatedwith amiodarone. Inmost cases, these elevations return towardnormal after a fewmonths, althoughamiodarone-induced hepatitis has been reportedinap- proximately 3% of patients. When hepatic transaminases remain chronically elevated, the consequences are unclear. Pulmonary complications are generally considered the most dan- gerousside effect seenwith amiodaroneand are the form of toxi- city most likely to prove fatal. Acute adult respiratory distress syn- drome from amiodarone-inducedpneumonitis can be seen at any time during therapy, but the timeofhighest risk is probably immedi- ately after surgery, especially cardiac surgery. A chronic interstitial brosis can also be seenwith amiodarone; the 94 Chapter 5 incidenceofthis problemis unclear. Therefore, routine pulmonary function tests do not appear to helpinpredicting which patients will eventually develop lung toxicity. Approximately 10% of patients treatedwith amiodarone eventually develop truehypothyroidism (a low serum T4 level isalways signicant in patients taking this drug), and a smaller proportiondevelop hyperthyroidism. Althoughhypothy- roidismcan be treated relatively easily with thyroid-replacement medication,hyperthyroidism represents a difcult clinical problem because of its presentation and its treatment. Amiodarone-induced hyperthyroidism sometimes manifests as an exacerbation of the pa- tients underlying ventricular tachyarrhythmias. Further, because amiodarone itself containsasig- nicantamountofiodine, patients receiving amiodarone have high- iodine stores, whichthus precludes the use of radioactive iodine for thyroid ablation. Tomake matters worse, treating amiodarone- induced hyperthyroidismwith antithyroid drugs can be difcult or even impossible. Sometimes thyroidectomy is the only feasible meansofcontrolling amiodarone-induced hyperthyroidism. Signicant photosensitivity occurs in about 20% of patients taking the drug,and some patients eventually develop ablue-gray discol- oration of sun-exposed skin, which can be quite disguring. Neurologic side effects are rare but can include ataxia, tremor, sleepdisturbances, and peripheral neuropathy. Ocular symptoms(most often, poor night vision or halo vision) occasionally accompany the corneal microdeposits seeninvirtually all patients taking amiodarone. Amiodarone canpotentiate the effect of beta blockers and calcium blockers and lead to negative inotropic effects and bradyarrhythmias. Sotalol Sotalol, a noncardioselective beta blocker, was initially developed as an antihypertensive agent. The drug is not metabolized; it isexcreted unchanged by the kidneys, and the dosage should be reducedinpatients with renal insufciency. Indications Sotalol isapproved for the treatmentofsignicantventricular ar- rhythmias but can be useful for treating all types of tachyarrhyth- mias. Adverse effects and drug interactions the major side effects of sotalol are related to its noncardioselective beta-blocking effects (e. Exacerbation of congestive heart failure is most commonly seeninpatients whose left ventricular ejection fractions are less than 0. So, for in- stance, if sotalol isbeing used to treat atrial brillation, the relative safety of using the drug. Thus, suchapatient shouldnever be senthome taking sotalol untilheor she has been observedinsinus rhythm. A multicenter randomized trial using D-sotalol in patients with ventricular arrhythmias was stopped be- cause of an excess of suddendeath in the D-sotalol arm. Clinical pharmacology After intravenous infusion, ibutilide is extensively metabolized to eight metabolites. More than 80% of the drug isexcretedinthe urine, only 7% as unmetabolizedibutilide. The drug issubjectto pronounced rst-pass metabolismwhengiven orally, which is why only the intravenous formis available. Dosage Ibutilide is infused as a 1-mg intravenous bolus during a period of 10 minutes.

They tend to be quite refractory to give the impression that they were provoked intentionally muscle relaxant drugs medication order 25mg imitrex amex. Typical in a clinical form of atopic dermatitis after exclusion of allergic contact adults; may appear self-inficted spasms bladder purchase imitrex without prescription. This condition occurs in a small percentage of patients spasms from acid reflux purchase cheapest imitrex, and clinical management is diffcult spasms prozac order imitrex 100mg with mastercard. Furthermore, it is likely that clinicians worldwide share this inclination owing to poor familiarity or resistance to the Figure 15. At times, the progress of exclusion and can only be determined after ruling out all and presence of psoriatic lesions in typical areas such as the of the other diseases included in the diferential diagnosis elbows, knees, nails, or scalp enable us to reach a diagnosis. In adult-onset eczema and psoriatic lesions, and although no thick plaques disease, performance of patch tests should always be based on are present, patients experience more intense itching than in clinical fndings. If the results are positive, we should determine whether they are relevant, and if so, eliminate or avoid the source of the Miscellaneous allergen. Differential Diagnosis of Atopic Dermatitis in Adults results with due caution, as the chances of an irritant patch reaction increase. However, only Ingredients in hygiene products (preservatives, fragrances, half of adult patients sensitized to 1 or more foods see any and emulsifers) and topical treatments may all act as contact improvement upon eliminating it from their diet. Practitioners should also remember to with chronic hand eczema who present itching and edema perform late readings to rule out allergy to corticosteroids. In these approval of standardized test materials, the atopy patch test cases, we advise carrying out the patch tests when possible, (for airborne allergens or foods) is not yet a part of routine even when conditions are not optimal, and interpreting the diagnostic recommendations [1,12,34,38]. Management of atopic dermatitis: are there with predominance of spongiosis in the acute phase and of differences between children and adults Adult onset atopic dermatitis: Under- such as cutaneous lymphoma (this may require multiple recognized or under-reported Thus, it is a diagnosis of exclusion that we can only reach Diagnosis and assessment of atopic dermatitis. Wollenberg A, Oranje A, Deleuran M, Simon D, Szalai Z, Kunz (eg, cutaneous lymphoma, dermatitis herpetiformis). Clinical Features of Adult/Adolescent Conflicts of Interest Atopic Dermatitis and Chinese Criteria for Atopic Dermatitis. Is there something called adult onset morphology of hand eczema in patients with atopic dermatitis. Gronhagen C, Liden C, Wahlgren C-F, Ballardini N, Bergstrom recommendations based on expert consensus opinion. Epidemiology, clinical features, and immunology of the intrinsic (non-IgEmediated) type of atopic dermatitis (constitutional dermatitis). This document is produced from elemental chlorine-free material and is sourced from sustainable forests. Both genetic and environmental factors are likely to contribute, with defects in epithelial barrier function arising from abnormalities in structural proteins such as filaggrin making the skin both excessively permeable and more prone to damage from environmental irritants and allergens. The most common progression of atopic eczema is for it to resolve during childhood, but it may persist into adult life or recur in the teenage or early adult years. Depending on disease severity, atopic eczema may have a considerable adverse effect on the quality of life of affected individuals (eg through sleep disturbance) and their families. Atopic eczema may adversely influence a childs emotional and social development and may predispose to psychological difficulties. In 2002 the cost of community dispensed prescriptions for topical corticosteroids for atopic eczema was estimated as 11. There appears to be real potential for improving the outcome of its treatment in the community8 and perhaps the cost effectiveness of treatment. It includes advice on the various topical treatments for atopic eczema (including emollients (moisturisers), topical corticosteroids, topical calcineurin inhibitors and dressings), anti-infective treatments (such as antibiotics and antiseptics), antihistamines, complementary therapies and the roles of diet and environmental factors. It excludes treatments that are usually carried out in secondary care, such as phototherapy and systemic immunosuppressant drugs. The studies cited use both terms, but for consistency, the condition is referred to as atopic eczema throughout the guideline. The term eczema describes a skin disorder that is usually itchy and which is characterised by observable changes that include redness, blistering, oozing, crusting, scaling, thickening and sometimes colour change although not all of these changes will necessarily occur together. The term atopic is used to describe conditions such as eczema, asthma, seasonal rhinitis and hay fever, which often have a genetic basis and may be associated with sensitisation to common environmental allergens. Adherence to guideline recommendations will not ensure a successful outcome in every case, nor should they be construed as including all proper methods of care or excluding other acceptable methods of care aimed at the same results. The ultimate judgement must be made by the appropriate healthcare professional(s) responsible for clinical decisions regarding a particular clinical procedure or treatment plan. It is advised, however, that significant departures from the national guideline or any local guidelines derived from it should be fully documented in the patients case notes at the time the relevant decision is taken. Some recommendations may be for medicines prescribed outwith the marketing authorisation (product licence). It is not unusual for medicines to be prescribed outwith their product licence and this can be necessary for a variety of reasons. Generally the unlicensed use of medicines becomes necessary if the clinical need cannot be met by licensed medicines; such use should be supported by appropriate evidence and experience. The prescriber should be able to justify and feel competent in using such medicines. The grade of recommendation relates to the strength of the supporting evidence on which the evidence is based. D patients should be referred to a dermatologist where there is: uncertainty concerning the diagnosis poor control of the condition or failure to respond to appropriate topical treatments psychological upset or sleep problems recurrent secondary infection. B patients with atopic eczema should be advised to apply topical corticosteroids once daily. The authors recommended the use of criteria in interventional studies as opposed to daily clinical management. A systematic review suggests that there is no evidence that atopic testing such as skin prick testing or measurement of specific immunoglobulin E (IgE) levels enhances the initial diagnosis 2+ of atopic eczema. Widespread herpes simplex (eczema herpeticum) should be considered in any patient with rapidly deteriorating atopic eczema. Some rare genetic disorders are associated with a pattern of cutaneous inflammation that resembles atopic eczema. These include Wiskott-Aldrich syndrome, anhidrotic ectodermal dysplasia, phenylketonuria, Nethertons syndrome, ataxia-telangiectasia and agammaglobulinaemia. Referral for consideration of food allergy investigation is discussed in section 11. D an emergency referral to a dermatologist or paediatrician should be arranged by telephone where there is clinical suspicion of eczema herpeticum (widespread herpes simplex). In two of the studies the interventions were effective in terms of reduced clinical severity scores. There was heterogeneity in the format (group and one to ++ 1 one), content and setting (nurse-led, multidisciplinary) of the interventions meaning that results could not be combined. The review also described the findings of studies examining various group and individual educational interventions for adult patients and how these may improve knowledge and understanding of treatments. Although long term emollient therapy is considered the mainstay of treating atopic eczema, a systematic review conducted in 2000 did not identify any high quality clinically relevant 1++ evidence in support of emollient monotherapy. It 4 recommends that healthcare professionals offer a range of emollients allowing selection of the most appropriate to the patient, and that prescriptions should be reviewed frequently. Table 3: Types of emollient products1 type Description Emollient creams and ointments these products are designed to be left on the skin.

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All peer review patients in most circumstances but that better evidence comments were blinded and sent to the Panel for could change confidence spasms in your sleep discount 50mg imitrex amex. In total spasms when excited purchase 25mg imitrex mastercard, 50 reviewers provided comments muscle relaxer 7767 buy genuine imitrex on-line, Grade C in support of a Strong or Moderate including 38 external reviewers spasms vs fasciculations imitrex 25mg online. At the end of the peer Recommendation indicates that the statement can be review process, a total of 622 comments were received. Expert urinary tract or pelvic surgery should be obtained, and Opinion refers to a statement, achieved by consensus patients should be queried as to travel history. It is also interventions can be evaluated, to determine the important to note the relationship of infections to appropriate pathway within the treatment algorithm, hormonal influences (e. As previously discussed, determining when a should be documented, noting the compartment and culture represents clinically significant bacteriuria must stage of any clinically significant prolapse. The bladder factor in the clinical presentation of a patient, the urine and urethra should be palpated directly for evidence of collection method used, and the presence of other urethral tenderness, urethral diverticulum, Skenes suggestive factors such as pyuria. A focused neurological exam to rule out occult neurologic Disorders such as interstitial cystitis/bladder pain defects may also be considered. Contamination of solutions, such as boric acid or other preservative urine specimens with skin and vaginal bacteria can solutions, demonstrate high agreement with the results result in high rates of suboptimal or unnecessary 95-98 of immediate culture. Thus, samples should either treatment, resulting in poor patient outcomes and 75 be transported to the lab in urine transport media in higher health care costs. While variably defined, bringing samples from home due to the high potential contamination should be suspected when the specimen for inadequate storage and erroneous results. When there is high contamination, halving the contamination rates seen suspicion for contamination, clinicians can consider without attention to this detail. Such instructions can even be to provide a sufficient quality specimen for analysis; placed on the wall of the clinic bathroom. Contamination of urinary samples varies considerably the vaginal and skin microbiota in asymptomatic due to multiple factors associated with urine collection women can contain many bacterial species thought of and storage. As urine can be easily seeded circumstances and in patients who may have a difficult with commensal flora, low numbers of contaminant time performing a high-quality clean-catch specimen bacteria can continue to proliferate when stored at (e. However, if a hematuria without infection or renal calculi, upper tract patient does not respond appropriately to treatment of imaging is recommended. Although no studies were pelvic surgery, cystoscopy can be helpful to assess for identified specifically designed to document direct anatomic abnormalities from the previous surgery, effects of procuring urinalysis and urine culture with including urethral stricture or obstruction, foreign body antibiotic sensitivities prior to initiating treatment, the such as mesh, bladder stones, fistula, or urethral/ Panel determined each episode should be clinically bladder diverticulum. As described previously, urinalysis can determine the presence of epithelial cells In a single-institutional cohort study of 163 women who 77 suggesting contamination. Such information from a had abdominopelvic imaging available, cystoscopy urinalysis may indicate that obtaining a catheterized identified only 9 cases of significant clinical findings. Of specimen is reasonable to accurately evaluate the those, only five cases were uniquely identified on 92 101 patients culture results; however, urinalysis provides cystoscopy and missed on imaging modalities. Of unlikely to be of value in the absence of symptoms of these women, 61% had at least one urine culture, upper tract disease or other gynecological problems in 6. There guide treatment decisions due to the poor sensitivity was no difference in risk of any adverse event (8. However, every effort should be situations, procurement of a urine culture will not be made to obtain microbiological data to confirm the possible and empiric therapy may be allowed in select diagnosis, follow clinical responses to management, and circumstances when the clinician deems such patients allow modification of treatment plans as needed. Self-start therapies should utilize the choices patients with acute episodes while awaiting of antibiotics that would be prescribed for acute urine cultures. In select circumstances, employing a shared decision- Antibiograms provide the clinician critical data making process with informed patients, initiation of a regarding choice of agents, particularly when selecting short treatment course of antibiotic therapy at the empiric antibiotics pending urine culture and sensitivity discretion of the patient (self-start) therapy may be results. Such information can typically be obtained from offered for acute symptomatic episodes in patients with a hospitals primary laboratory. Clinicians should omit surveillance urine women, and 2) patients undergoing elective urologic testing, including urine culture, in surgery. Prospective observational recommend the routine treatment of urease-producing studies have found no differences in rates of bacteriuria (including P. However, all analyses fluoroquinolones or nitrofurantoin with respect to risk of were based on small numbers of trials; no antibiotic resistance or other adverse events (e. There were no statistically significant not all harms were reported for all comparisons. In addition to the small number of trials available for each comparison within the systematic review also found no differences the network, other shortcomings of this analysis include between nitrofurantoin or fluoroquinolones versus - failure to report direct and indirect estimates lactams in short or long-term symptomatic or 113 separately, the consistency between direct and indirect bacteriological cure. Data on risk of resistance relatively little to distinguish one agent from another. A recommended for empiric use in areas in which local network meta-analysis was performed with results 91 resistance rates exceed 20%. Generally, all effects on short- or long-term bacteriological failure antibiotics have risks; as such, stewardship should be was not statistically significant. A three-day course of exercised to balance symptom resolution with reduction antibiotics was associated with decreased risk of in risk of recurrence. Overall, antibiotic prophylaxis reduced the number of the duration of preventive treatment ranged from 6 to clinical recurrences when compared to placebo in pre- 12 months. The results of was 50 years; in the other the trials on prophylactic antibiotics consistently trials the mean age was in the 30s or low 40s, so both demonstrate the positive effect of this preventive peri- and post-menopausal women and younger pre- treatment, while acknowledging the increase in mild, menopausal women have been studied in these trials. The effect of the antibiotic prophylaxis prophylaxis ranged from 2 to 7 in trials that reported lasted during the active intake time period. The rate of possible serious pulmonary or use of fluoroquinolones, such as ciprofloxacin, for hepatic adverse events has been reported to be prophylactic antibiotic use is not recommended in 155 0. These There is little evidence on the benefits of rotating patients were more likely to have long-term exposure antibiotics used for prophylaxis. In a different to nitrofurantoin, highlighting the need for caution population of inpatient hospital treatment of infection, when prescribing long-term and avoiding nitrofurantoin informed switching strategies,149,150 have been used in patients with chronic lung disease. However, there is 158 Beers Criteria, with the strength of recommendation not enough evidence in the existing published literature as strong and a listed quality of evidence of low. The to reach reliable conclusions regarding the efficacy of 2015 Beers update has been modified to recommend cycling antibiotics as a means of controlling antibiotic avoidance of nitrofurantoin when creatinine clearance is resistance rates. Nitrofurantoin-induced lung injury can estimates were inconsistent, and occur in the acute, subacute or chronic setting, most nitrofurantoin was associated with increased risk of 165 commonly presenting with a dry cough and dyspnea. In a 1980 nitrofurantoin and other antibiotics in risk of 151 analysis of 921 reported cases by Holmberg et al. Other side effects monitoring is important to avoid the potential adverse included vaginal and oral candidiasis, skin rash, and events associated with nitrofurantoin. One of the trials compared disturbances), decreased oxygen carrying capacity a single dose of antibiotics for exposures to different (e. The other intermittent dosing trial gestational age, hyperbilirubinemia), interactions with compared a single dose of ciprofloxacin after sexual other drugs (e. In clinical practice, the In general, there is sparse reporting of antibiotic duration of prophylaxis can be variable, from three to resistances, with little data specifically on the impact of six months to one year, with periodic assessment and long-term antibiotic therapy on antibiotic resistance. Some women continue continuous or post- There are data on the effects of antibiotic prescribing coital prophylaxis for years to maintain the benefit on antimicrobial resistance in individual patients. The dosing options for continuous participants), the pooled odds ratio for resistance was prophylaxis include the following: 2. As such, even transient use of antibiotics can affect the carriage of resistant organisms Nitrofurantoin monohydrate/macrocrystals 100mg and impact the endemic level of resistance in the daily population. Four trials compared different sexual activity, antibiotic prophylaxis taken before or antibiotic dosing strategies. Additionally, has been the subject of an increasing number of intermittent dosing is associated with decreased risk of randomized clinical trials.

Global and right ventricular tachycardia: a repetitive rhythmic activity poss- atrial mapping of human atrial utter: the presence of ibly related to afterdepolarization spasms rib cage area order imitrex with a mastercard. Electrophysiologic and pharmaco- the crista terminalis in patients with typical atrial utter: logic characteristics of automatic ectopic atrial tachycardia back spasms 26 weeks pregnant order 50mg imitrex. Radiofrequency catheter ablation of atrial tachycar- [54] Tsuchiya T spasms and pain under right rib cage buy imitrex mastercard, Okumura K infantile spasms 4 months best order imitrex, Tabuchi T, Iwasa A, Yasue H, dias. The upper turnover site in the reentry circuit of [34] Pappone C, Stabile G, de Simone A et al. Transcatheter ablation of mapping of the common atrial utter circuit in the right ectopic atrial tachycardia in young patients using radio- atrium. Mechanism and anatomic wave conguration during atrial tachycardia to predict site substrate. Supraventricular tachycardia due to multiple atrial eter ablation of inferior vena cava-tricuspid annulus isthmus ectopic foci: a relatively common problem. Radiofrequency mapping and the study of supraventricular tachycardia ablation of atrial utter: ecacy of an anatomically guided (separatas 13. Mechanism of atrial reentry as a mechanism for atrial utter induced by initiation of atrial utter in humans: Site of unidirectional acetylcholine and rapid pacing in the dog. Characterization of mapping studies during induced atrial brillation in the low right atrial isthmus as the slow conduction zone and sterile pericarditis model. Insights into the mechanism of its pharmacological target in typical atrial utter. Mech- cardial mapping in the human left ventricle using a non anisms of induction of typical and reversed atrial utter. Spontaneous onset of Type I atrial entrant tachycardia after the Senning or Mustard procedure utter in patients. Cholinergically mediated tachyarrhythmias induced by a radiofrequency catheter therapy of paroxysmal atrial bril- single extrastimulus in the isolated canine right atrium. Ablation of incisional reentrant atrial tachy- microreentrant sources as a mechanism of atrial brillation cardia complicating surgery for congenital heart disease: use in the isolated sheep heart. Sinus reentrant tachycardias resulting from previous atrial surgery: nodal responses to atrial extrastimuli in patients without localizing and transecting the critical isthmus. Atrio-atrial symptomatic sinus node reentrant tachycardia: Incidence, conduction after orthotopic heart transplantation. J Am Coll Cardiol 1985; 5: [81] Saoudi N, Redonnet M, Anselme F, Poty H, Cribier A. Sinus node reentry: a mechanism for supraven- atrial arrhythmia after orthotopic heart transplantation. Demonstration of sustained sinus and atrial utter originating in the right atrial free wall. Acceleration of typical atrial [104] Saoudi N, Koning R, Eltchanino H, Cribier A, Letac B. The sinus node starts each heartbeat by generating a small amount of electricity, which spreads into the muscle cells of the atria. Next, the electrical activity moves into the junction between the atria and ventricles. It takes the signal coming from the atria, delays it slightly, then passes it into the ventricles, which causes them to beat. The brain tells the sinus node how fast to beat; it can speed up during exercise or in times of stress and slow down when resting or sleeping. Diagnosis Arrhythmias are abnormalities of the heart rate and rhythm (sometimes felt as palpitations). Some patients with otherwise normal hearts can have abnormal electrical pathways in their hearts that cause arrhythmias. Patients with underlying problems in the function and structure of the heart are more prone to heart rhythm problems. As patients whove had successful heart surgery live longer, doctors are diagnosing more heart rhythm abnormalities. A heart rhythm abnormality is evaluated in ways much like those used to evaluate other health problems. The history of your symptoms, including sensation of your heart beating fast, dizziness and fainting are very important. Symptoms include palpitations, chest pains, upset stomach, decreased appetite, lightheadedness or weakness. Straining, such as closing the nose and mouth and trying to breathe out, may work. Once the rhythm returns to normal, proper therapy with drugs can usually prevent future episodes. This is a fast heart rate that starts in the hearts upper chambers and is conducted to the lower chambers. Its common after surgery that involves the atria (upper chambers), especially the Mustard, Senning and Fontan operations and in conditions that cause the atria to enlarge (most commonly from leakage or blockage or the mitral or tricuspid valves inside the heart). Besides a fast heart rate, other symptoms are fatigue, dizziness, lightheadedness and fainting. Ventricular Tachycardia this is a fast heart rate that starts in the hearts lower chambers. It usually results from serious heart disease and often requires prompt or emergency treatment. Treatment options include medication, radiofrequency ablation and implanting a device (defibrillator) that shocks the heart into a normal rhythm or surgery. Patients may have no symptoms or may have fatigue, exercise intolerance, dizziness or fainting. Complete Atrioventricular Block (complete heart block) Complete heart block occurs when the electrical signal cant pass normally from the hearts upper to lower chambers. These cant cure an arrhythmia, but they can improve symptoms by preventing episodes from starting, slowing the heart rate during an episode or shortening how long an episode lasts. Many side effects arent serious and go away when the dose is changed or the medication stopped. Some side effects are very serious and may require that you be admitted to the hospital to start the medication. If the medicine must be taken to prevent fast heart rate problems, a pacemaker may be necessary. Because of the side effects, its very important to take the medicine exactly as the doctor prescribes it. One risk of chronic heart rhythm abnormalities is blood clots forming in the heart, especially its upper chambers. If a clot breaks off, it can be carried to other parts of the body, such as the lung or brain, and cause serious problems. Anticoagulants (medication to help prevent blood clots) are given to prevent this from happening. Radiofrequency Ablation Radiofrequency ablation is done during an intracardiac electrophysiologic procedure. Then the catheters tip is heated by radiofrequency waves to alter a small area of the heart. Its success is directly related to the cause of the arrhythmia and the complexity of the underlying congenital heart disease.