Anil K. Bhandari

Development and Validation of the Atrial Fibrillation Effect on QualiTy-of-Life (AFEQT) Questionnaire in Patients With Atrial Fibrillation

Background—Atrial fibrillation (AF) has a deleterious impact on health-related quality-of-life (HRQoL), but measuring this outcome is difficult. A comprehensive, validated, disease-specific questionnaire to measure the spectrum of QoL domains affected by AF and its treatment is not available. We developed and validated a 20-item questionnaire, Atrial Fibrillation Effect on QualiTy-of-life (AFEQT), in a 6-center, prospective, observational study. Methods and Results—Factor analyses established 4 conceptual domains (Symptoms, Daily Activities, Treatment Concern, and Treatment Satisfaction) from which individual domain and global scores were calculated. Participants from 6 centers completed the AFEQT at baseline, at month 1, and at month 3. Psychometric analyses included internal consistency and known-group validity. Test-retest reliability was assessed by comparing 1-month changes in scores among those with no change in therapy. Effect size was used to assess responsiveness after intervention. Among 219 patients age 62±11.9 years, 94% completed the AFEQT at baseline and 3 months; 66% had paroxysmal, 24% persistent, 5% longstanding persistent, and 5% permanent AF. Internal consistency was >0.88 for all scales. Lower AFEQT scores were observed with increased AF severity, categorized as asymptomatic, mild, moderate and severe, respectively: 71.2±20.6, 71.3±19.2, 57.9±19.0, and 42.0±21.2. Intraclass correlations for Overall, Symptoms, Daily Activities, Treatment Concern, and Satisfaction scores were 0.8, 0.5, 0.8, 0.7, and 0.7, respectively. Changes in 3-month scores were larger after ablation than with pharmacological adjustments, and both were greater than those observed in stable patients. Conclusions—This initial validation of AFEQT supports its use as an outcome in studies and a means to clinically follow patients with AF.

Electrophysiologic effects of intravenous magnesium in patients with normal conduction systems and no clinical evidence of significant cardiac disease

Parenteral magnesium has been used for several decades in the empiric treatment of various arrhythmias, but the data on its electrophysiologic effects in man are limited. We evaluated the electrophysiologic effects of magnesium sulfate (MgSO4) administration in eight normomagnesemic patients with normal mononuclear cell magnesium content, who had no clinically significant heart disease and had normal baseline electrophysiologic properties. After administration of intravenous MgSO4, serum magnesium rose significantly from 1.9 +/- 0.1 to 4.4 +/- 1.7 mg/dl (p less than 0.02). During a maintenance magnesium infusion, we observed significant prolongation of the ECG PR interval (145 +/- 18 to 155 +/- 26 msec, p less than 0.05), AH interval (77 +/- 27 to 83 +/- 26 msec, p less than 0.002), antegrade atrioventricular (AV) nodal effective refractory period (278 +/- 67 to 293 +/- 67 msec, p less than 0.05), and sinoatrial conduction time (60 +/- 34 to 76 +/- 32 msec, p less than 0.02). No significant effect was observed on sinus cycle length, sinus node recovery time, intra-atrial or intraventricular conduction times, QRS duration (during both sinus rhythm and ventricular pacing), QT interval, HV interval, paced cycle length resulting in AV nodal Wenckebach block, AV nodal functional refractory period, retrograde ventriculoatrial (VA) effective refractory period, or atrial and ventricular refractory periods. These findings, in conjunction with the demonstrated ability of magnesium to block slow channels for sodium movement, may provide an explanation of the mechanism by which magnesium exerts its effect in the treatment of atrial and junctional arrhythmias.

Flecainide acetate prevents recurrence of symptomatic paroxysmal supraventricular tachycardia. The Flecainide Supraventricular Tachycardia Study Group.

Oral flecainide acetate was administered to 34 patients with documented symptomatic paroxysmal supraventricular tachycardia (PSVT) with a double-blind, placebo-controlled, 8-week crossover trial design. PSVT was defined as a regular tachycardia of at least 120 beats/min without evidence of atrioventricular dissociation. The study required considerable patient cooperation. Patients first entered a 4-week qualifying phase followed by a 3-week, open label, flecainide dose-ranging phase. They were then randomized in a blind fashion to receive either placebo or tolerated flecainide dose for an 8-week treatment period and then crossed over after four symptomatic documented episodes of PSVT or at the end of the treatment period. By all efficacy parameters analyzed, flecainide was superior to placebo. Flecainide was associated with an actuarial 79% freedom from symptomatic PSVT events compared with only 15% on placebo at 60 days (p less than 0.001). Of the 34 patients, 29 had recurrence of symptomatic PSVT at least once during the placebo phase; only eight patients had a recurrence during the flecainide phase (p less than 0.001). The median time to the first symptomatic PSVT event was 11 days in the placebo group and greater than 55 days in the flecainide group (p less than 0.001). Likewise, the interval between attacks was a median of 12 days on placebo compared with more than 55 days on flecainide (p less than 0.001). Finally, the flecainide slowed symptomatic PSVT heart rates to 143 +/- 12 beats/min from 178 +/- 12 on placebo (p less than 0.02) in the seven patients who had events in the placebo and flecainide treatment phases.(ABSTRACT TRUNCATED AT 250 WORDS)

Ranolazine, an antianginal agent, markedly reduces ventricular arrhythmias induced by ischemia and ischemia-reperfusion.

We tested the effect of the antianginal agent ranolazine on ventricular arrhythmias in an ischemic model using two protocols. In protocol 1, anesthetized rats received either vehicle or ranolazine (10 mg/kg, iv bolus) and were subjected to 5 min of left coronary artery (LCA) occlusion and 5 min of reperfusion with electrocardiogram and blood pressure monitoring. In protocol 2, rats received either vehicle or three doses of ranolazine (iv bolus followed by infusion) and 20 min of LCA occlusion. With protocol 1, ventricular tachycardia (VT) occurred in 9/12 (75%) vehicle-treated rats and 1/11 (9%) ranolazine-treated rats during reperfusion (P = 0.003). Sustained VT occurred in 5/12 (42%) vehicle-treated but 0/11 in ranolazine-treated rats (P = 0.037). The median number of episodes of VT during reperfusion in vehicle and ranolazine groups was 5.5 and 0, respectively (P = 0.0006); median duration of VT was 22.2 and 0 s in vehicle and ranolazine rats, respectively (P = 0.0006). With protocol 2, mortality in the vehicle group was 42 vs. 17% (P = 0.371), 10% (P = 0.162) and 0% (P = 0.0373) with ranolazine at plasma concentrations of 2, 4, and 8 microM, respectively. Ranolazine significantly reduced the incidence of ventricular fibrillation [67% in controls vs. 42% (P = 0.414), 30% (P = 0.198) and 8% (P = 0.0094) in ranolazine at 2, 4, and 8 microM, respectively]. Median number (2.5 vs. 0; P = 0.0431) of sustained VT episodes, incidence of sustained VT (83 vs. 33%, P = 0.0361), and the duration of VT per animal (159 vs. 19 s; P = 0.0410) were also significantly reduced by ranolazine at 8 microM. Ranolazine markedly reduced ischemia-reperfusion induced ventricular arrhythmias. Ranolazine demonstrated promising anti-arrhythmic properties that warrant further investigation.

Postconditioning Markedly Attenuates Ventricular Arrhythmias After Ischemia-Reperfusion

Background: Brief periods of reocclusion (postconditioning) during early reperfusion reduce myocardial infarct size. Whether postconditioning has an effect on lethal ventricular arrhythmias independent of infarction in an in-vivo regional ischemia model is unknown. The purpose of this study was to determine if postconditioning limited reperfusion arrhythmias in a necrosis-free model. Methods: Anesthetized rats were subjected to 5 minutes of proximal coronary artery occlusion; they were randomized to a control group (n = 15) that underwent reperfusion alone or a postconditioning group (n = 15) that received four cycles of 20 seconds reperfusion, 20 seconds reocclusion before final reperfusion. Results: During the final reperfusion phase, ventricular arrhythmias occurred in 14 of 15 control rats and 8 of 15 postconditioning rats (P = .017). Ventricular tachycardia occurred in 10 of 15 control rats vs 4 of 15 postconditioning rats (P = .028). Control rats demonstrated 1.3 runs of ventricular tachycardia per minute vs 0.4 runs in postconditioning rats (P = .026). The average duration of ventricular tachycardia runs was 8.8 ± 3.2 seconds in the control group vs 5.0 ± 3.9 seconds in postconditioning rats (P = NS). Conclusion: This in-vivo study showed that postconditioning markedly attenuates ventricular arrhythmia after regional ischemia in a noninfarct model.

Fetal and neonatal adverse effects profile of amiodarone treatment during pregnancy.

During pregnancy amiodarone has been used for treatment of arrhythmias in both the motherleg and the fetus.i0-14 Although the initial data on the use of amiodarone in pregnancy revealed no teratogenicity and only few minor adverse effects,‘-* other recent reports93 l3 described two cases of neonatal hypothyroid goiter, casting doubts on the safety of amiodarone during pregnancy. We report a clinical case of maternal amiodarone treatment for ventricular tachycardia (VT) during conception and throughout two successive pregnancies. A 29-year-old woman with a history of symptomatic ventricular arrhythmia refractory to treatment with beta blockers, quinidine, procainamide, and tocainide underwent extensive evaluation of arrhythmia because of worsening symptoms before she became pregnant with her third child. Previously she had had two normal pregnancies (both births at 40 week’s gestation; birth weight 2945 gm and 3000 gm, respectively) and two abortions. She also had mitral and tricuspid valve prolapse and a history of right upper lobectomy for drug-resistant pulmonary tuberculosis. Left and right ventricular size and function were normal, and there was no evidence of cardiomyopathy or right ventricular dysplasia. The diagnosis of arrhythmia was confirmed by ambulatory ECG (Holter) monitoring, which revealed up to 759 runs of nonsustained VT. During electrophysiologic testing she had inducible sustained monomorphic VT that degenerated into ventricular fibrillation. The patient was started on a regimen of amiodarone, which effectively suppressed the VT and completely relieved the symptoms. After 2 years of treatment the patient became pregnant while taking amiodarone, 400 mglday. The patient and her husband were informed in detail about the uncertainty and potential danger of amiodarone treatment during pregnancy; abortion was considered and discussed on several occasions, and the patient refused. Because of symptomatic relief the patient elected to continue amiodarone therapy during pregnancy. The patient was first seen in our clinic at 12 weeks’ gestation; at that time, to decrease the risk of adverse effects, the dosage of amiodarone was decreased to 200 mglday, and the patient was maintained on this dosage. Throughout the pregnancy se-

Frequency and significance of induced sustained ventricular tachycardia or fibrillation two weeks after acute myocardial infarction.

Electrophysiologic study, 24-hour ambulatory electrocardiographic monitoring, treadmill exercise test and angiographic evaluations were performed in 45 patients 14 +/- 3 days (mean +/- standard deviation) after acute myocardial infarction. Electrophysiologic study protocol included burst ventricular pacing and 1 to 3 ventricular extrastimuli at 2 cycle lengths from right ventricular apex, right ventricular outflow and left ventricle. Sustained monomorphic ventricular tachycardia (VT) (13 patients) or ventricular fibrillation (VF) (7 patients) was induced in 20 patients (44%) (group I). In these 20 patients, VT/VF was inducible with 2 extrastimuli in 10 patients, 3 extrastimuli in 9 patients and burst pacing in 1 patient. In the remaining 25 patients (56%), induction of no fewer than 7 ventricular beats were noted (group II). Severe left ventricular (LV) wall motion abnormalities occurred in 70% of group I patients and 22% of group II patients (p less than 0.005). There was no difference in the site of infarction, frequency and grade of ventricular ectopic rhythm on ambulatory electrocardiographic monitoring, double product on submaximal exercise, LV ejection fraction, and number of obstructed coronary arteries (70% or greater) (p greater than 0.1) between group I and group II patients. During a mean follow-up of 10 +/- 3 months, 1 patient in each group died suddenly, and in 1 group I patient spontaneous sustained VT developed which was identical in morphologic configuration to that induced during electrophysiologic study. In conclusion, electrical induction of sustained VT or VF during electrophysiologic study is common in patients 2 weeks after acute myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for stunned myocardium in humans: a 2001 update.

This article describes clinical situations in which stunning occurs and updates previous reviews on the topic. Stunning following angioplasty, angina and exercise‐induced ischemia, infarction, and after cardiac surgery are described. In addition, newer concepts regarding stunning, including neurogenic stunned myocardium, are discussed. Left atrial stunning following cardioversion is a recently recognized phenomenon with important clinical implications, but differs from the original concept of post‐ischemic stunning.

Decline in inducibility of sustained ventricular tachycardia from two to twenty weeks after acute myocardial infarction

To determine temporal evolution of sustained ventricular arrhythmias inducible after acute myocardial infarction (AMI), serial programmed ventricular stimulation (PVS) was performed in 27 patients 15 +/- 4 and 150 +/- 28 days after AMI. These patients did not have worsening of congestive heart failure or angina, coronary artery bypass surgery or spontaneous sustained ventricular tachycardia (VT) in the period between 2 PVS studies. During initial PVS, sustained VT or ventricular fibrillation (VF) was inducible in 17 patients (group I) and was not inducible in 10 (group II). Late PVS in group I induced sustained VT or VF in 8 patients (47%) and nonsustained VT or no VT in 9 (53%). A decrease in late inducibility of sustained VT/VF was greater for arrhythmias induced during initial PVS by triple extrastimuli and burst pacing than for those induced by double extrastimuli (88% vs 25%, p less than 0.04), but appeared to be unrelated to the morphologic characteristics or cycle length of the initially induced sustained VT or VF and to other clinical, hemodynamic or angiographic variables. During late PVS in 10 group II patients, sustained VT or VF remained noninducible in 9 (90% concordance); in 1 patient sustained VT was induced. During a mean follow-up of 14 +/- 5 months since late PVS, none of 27 patients had spontaneous sustained VT and 2 patients in group I died suddenly.(ABSTRACT TRUNCATED AT 250 WORDS)

Torsade de pointes and marked QT prolongation in association with hypothyroidism.

Excerpt Sustained ventricular tachyarrhythmias occur infrequently in patients with hypothyroidism (1, 2). In all previous reports (3-8), the morphologic features of ventricular tachyarrhythmias wer...