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Ventricular arrhythmia is a condition in which the normal, regular beating of the ventricular chambers of the heart is interrupted by irregularities in the pattern of contraction. Excessively fast, slow, or unstable ventricular contraction is not conducive to proper circulatory function and must be controlled. Amiodarone is an anti-arrhythmic drug that has been used for almost 30 years in the treatment of this condition; relatively serious side effects delayed the release of this drug in the United States until 1984, at which time it was approved only for the treatment of arrhythmia that was refractory (unresponsive) to less toxic drugs. A case is reported of a 29-year-old woman with a long history of severe ventricular arrhythmia that did not respond to first-line anti-arrhythmic medications (beta blockers, quinidine, procainamide, and tocainide), requiring her to rely on amiodarone for symptomatic relief. During the course of treatment, the patient became pregnant. She chose to continue the pregnancy as well as the amiodarone treatment, and at 38 weeks gestation gave birth to a female infant. Physical examination of the child did not reveal any organ abnormalities, but she was below the 10th percentile in body weight and was classified as small for gestational age. This categorization, although relatively benign, has a worse prognosis than normal weight for childhood illness and mortality. Five months after delivering this infant, the patient became pregnant again, and gave birth at 35.5 weeks (i.e., prematurely) to a male infant of normal body weight. Again, physical examination of the child revealed no abnormalities. At no time during either of the pregnancies or following the births did either the mother or the children exhibit any evidence of thyroid dysfunction, a relatively common adverse side effect of amiodarone treatment. In previously reported cases of neonatal complications (spontaneous abortion, death, heart murmur, etc.), thyroid dysfunction was implicated. Amiodarone treatment during pregnancy may, in the presence of normal thyroid function, not be linked with serious neonatal difficulties. (Consumer Summary produced by Reliance Medical Information, Inc.)

People who recover from cardiac arrest are at risk of suffering a recurrent episode. A subset of this group (60 to 80 percent) exhibits abnormalities in heart function during electrocardiogram (ECG) testing; these patients respond well to medication that alleviates the abnormalities. This improvement appears to prevent recurrence of cardiac arrest. The remaining 20 to 40 percent of patients show no abnormalities during ECG testing; this group is thought to be at a particularly high risk for sudden cardiac death. Seventy-one survivors of a single episode of cardiac arrest were evaluated. During testing, 26 of these patients had no inducible ECG abnormalities, such as ventricular tachycardia (abnormally rapid patterns of contraction of the ventricle). After a 16-month follow-up, 11 of the 26 patients suffered recurrent cardiac arrest, and 10 of these patients died. Analysis of the clinical data pertaining to these patients revealed that several variables were more likely to be associated with recurrent cardiac arrest. Among the 11 patients who suffered a recurrence, 55 percent had dilated cardiomyopathy (a defect in the functioning of the heart muscle), and 64 percent experienced premature ventricular contractions. Twenty-four-hour ambulatory ECG-guided therapy (wearing a portable ECG machine) did not improve the survival rate for these patients. Further studies are needed to determine the optimal treatment strategy for this high-risk group of patients. (Consumer Summary produced by Reliance Medical Information, Inc.)

The role of oral anticoagulants (OAC) in atrial fibrillation (AF) is well established. However, none of the randomized controlled trials included patients with end-stage renal disease (ESRD) leaving a lack of evidence in this large, challenging and unique patient group. Patients on hemodialysis (HD) with AF have additional risk factors for stroke due to vascular comorbidities, HD treatment, age, and diabetes. Conversely, they are also at increased risk of major bleeding due to uremic platelet impairment. Anticoagulants increase bleeding risk in patients with ESRD and HD up to 10-fold compared with non chronic kidney disease (CKD) patients on warfarin. There are conflicting data and recommendations regarding use of OACs in ESRD which will be reviewed in this article. We conclude by proposing a modified strategy for OAC use in ESRD based on the latest evidence. [ABSTRACT FROM AUTHOR]

Ventricular aneurysms (ballooning of the walls of the lower heart chamber) have many causes, with coronary artery disease being the cause in 75 percent of cases. Infrequently, no cause can be found; these are idiopathic cases. A case is reported of a 56-year-old woman with three idiopathic left ventricular aneurysms. For four years, prior to hospitalization, the patient had dyspnea (shortness of breath) on exertion, which was diagnosed as mild congestive heart failure. She had no other history of disorders which could contribute to ventricular tachycardia (rapid heartbeat), the symptom for which she was hospitalized. Her heart rate was 200 beats per minute (bpm), while the normal rate is 72 bpm. The initial chest X-ray showed no abnormal bulges indicative of aneurysms. Invasive imaging techniques were needed to reveal the aneurysms. Ventricular tachycardia was not responsive to drugs, and a device was implanted to restore normal heart rhythm. All previously reported cases of ventricular aneurysms were of single aneurysms, all of which were associated with arrhythmias. The study suggests this is a case of true idiopathic disease, as little or no evidence was found for known causes such as coronary artery disease, thrombi (clots), Chagas disease (a parasitic infection), or syphilis. (Consumer Summary produced by Reliance Medical Information, Inc.)

Atrial fibrillation is the most common cardiac arrhythmia and leads to an increased risk of stroke, heart failure, and death in affected patients. Despite a plethora of treatment modalities and many advances in our understanding of atrial fibrillation mechanisms and natural history, the management of patients with atrial fibrillation continues to pose many challenges. This review provides a concise discussion on the role of various pharmacologic and nonpharmacologic therapies that are currently being utilized. The recommendations are evidence based and take into account the findings of many recently conducted outcome trials in atrial fibrillation. [ABSTRACT FROM AUTHOR]

In patients with history of sustained ventricular tachyarrhythmias, the efficacy and safety of moricizine have not been systematically evaluated by electrophysiological studies. We performed electrophysiological testing in these patients in the drug-free state and then after moricizine loading, and evaluated the safety profile of moricizine during in-hospital loading and follow-up. The study population comprised of 31 patients with clinically sustained ventricular tachyarrhythmia. The underlying heart disease was coronary in 25 patients, cardiomyopathy in 5 patients, and none in 1 patient. The left ventricular (LV) ejection fraction ranged from I5%-69% (mean 39 ± 15%). During the baseline drug-free electrophysiological testing, sustained ventricular tachycardia was inducible in 27 patients, ventricular fibrillation in 1 patient, and reproducible, nonsustained ventricular tachycardia (15-25 sec) in 3 patients. All 31 patients received moricizine to the maximum tolerated dose (851 ± 185 mg) over a period of 2-7 days. Six patients developed ventricular proarrhythmia within the first 4 days. Proarrhythmia required multiple cardioversions in three patients, was not associated with QT prolongation, and spontaneously resolved 6-24 hours after withdrawal of moricizine. Of the remaining 25 patients, 24 underwent electrophysioiogical testing on moricizine and 4 patients (16%) were rendered noninducible. The VT cycle length in the other 20 patients slowed from 243 ± 30 msec to 299 ± 60 msec (P < 0.09). Four noninducible patients, two patients with inducible but slowed VT and one patient who had refused further testing were discharged on moricizine. Among these seven patients, recurrent arrhythmic events occurred in two patients, ventricular proarrhythmia in one patient, complete AV block in one patient, and severe disabling headache in one patient. Only two patients have continued to take moricizine without side effects or recurrent arrhythmic events during a follow-up of 4 months and 9 months, respectively. Moricizine is only rarely effective for long-term treatment of patients with spontaneous sustained ventricular tachyarrhythmias, It renders ventricular tachyarrhythmias noninducible in a small minority (16%) and is associated with a high incidence (23%) of ventricular proarrhythmias. [ABSTRACT FROM AUTHOR]

This study evaluated the role of serial electropharmacological testing on combination therapy with mexiletine and procainamide in 20 patients with inducible sustained ventricular tachycardia (VT) refractory to intravenous procainamide. The clinical arrhythmias were cardiac arrest in five patients, sustained VT in 11 patients, and recurrent syncope of presumably arrhythmic origin in four patients. The mean left ventricular ejection fraction (LVEF) was 0.40 ± 0.12 (mean ± SD). All patients had inducible sustained VT at baseline and after administration of intravenous procainamide. All 20 patients underwent electropharmacological testing on combination therapy with mexiletine and procainamide. The mean cycle length of inducible sustained VT was 251 ± 48 ms at baseline, 324 ± 81 ms on intravenous procainamide (P < 0.014 vs baseline), and 365 ± 82 ms on combination therapy (P < 0.0001 vs baseline, P = NS vs intravenous procainamide). Combination therapy did not suppress VT inducibility, nor did it make VT more difficult to induce in 19 of 20 patients. The remaining one patient had a partial response (runs of nonsustained VT, longest 10 seconds). Furthermore, combination therapy did not significantly prolong the VT cycle length over and above that observed during testing with intravenous procainamide. Therefore, in patients with inducible sustained VT refractory to procainamide during initial electropharmacological testing, mexiletine in combination with procainamide appears to be of little or no value and serial electropharmacological testing on these drugs is of limited usefulness. Early initiation of alternative therapy may be the preferred clinical option. [ABSTRACT FROM AUTHOR]

We report the case of a patient who developed a life-threatening polymorphous ventricular tachycardia [PVT] after six weeks of treatment with amiodarone. The Q-T interval was markedly prolonged at 0.86 second. The drug induction of PVT was strongly suggested by the fact that PVT resolved four days after withdrawal of amiodarone when the Q-T interval had shortened to 0.60 second; the arrhythmia has not recurred in the nine months of follow-up since then. Amiodarone, though a very effective antiarrhythmic agent, may induce serious PVT. [ABSTRACT FROM AUTHOR]

Background: Radiofrequency catheter ablation is used to treat recurrent ventricular tachycardia (VT).Objectives: This study evaluated long-term safety and effectiveness of radiofrequency catheter ablation using an open-irrigated catheter.Methods: Patients with sustained monomorphic ventricular tachycardia associated with coronary disease were analyzed for cardiovascular-specific adverse events within 7 days of treatment, hospitalization duration, 6-month sustained monomorphic ventricular tachycardia recurrence, quality of life measured by the Hospital Anxiety and Depression Scale, long-term (1-, 2-, and 3-year) survival, symptomatic VT control, and amiodarone use.Results: Overall, 249 patients, mean age 67.4 years, were enrolled. The cardiovascular-specific adverse events rate was 3.9% (9 of 233) with no strokes. Noninducibility of targeted VT was achieved in 75.9% of patients. Post-ablation median hospitalization was 2 days. At 6 months, 62.0% (114 of 184) of patients had no sustained monomorphic ventricular tachycardia recurrence; the proportion of patients with implantable cardioverter-defibrillator shocks decreased from 81.2% to 26.8% (p < 0.0001); the frequency of VT in implantable cardioverter-defibrillator patients with recurrences was reduced by ≥50% in 63.8% of patients; and the proportion with normal Hospital Anxiety and Depression Scale scores increased from 48.8% to 69.1% (p < 0.001). Patient-reported VT remained steady for 1, 2, and 3 years at 22.7%, 29.8%, and 24.1%, respectively. Amiodarone use and hospitalization decreased from 55% and 77.2% pre-ablation to 23.3% and 30.7%, 18.5% and 36.7%, 17.7% and 31.3% at 1, 2, and 3 years, respectively.Conclusions: Radiofrequency catheter ablation reduced implantable cardioverter-defibrillator shocks and VT episodes and improved quality of life at 6 months. A steady 3-year nonrecurrence rate with reduced amiodarone use and hospitalizations indicate improved long-term outcomes. (NaviStar ThermoCool Catheter for Endocardial RF Ablation in Patients With Ventricular Tachycardia [THERMOCOOL VT]; NCT00412607). [ABSTRACT FROM AUTHOR]

Recently, the routine use of dual-chamber implantable cardioverter defibrillators (DC-ICD) has been advocated over the single-chamber version (SC-ICD), but there are few reports of the frequency of complications between the 2 types of ICDs. Between July 1997 and April 1999, 178 consecutive patients underwent implantation of either a transvenous SC-ICDs (n=104) or a DC-ICDs (n=74). Twelve (16%) of the 74 patients with a DC-ICD had a total of 16 major complications compared with 6 (6%) of the 104 patients with a SC-ICD (p=0.01). The 16 DC-ICD complications included atrial lead dislodgment (4), ventricular lead malfunction (4), and pocket infection/hematoma (3), and the 6 SC-ICD complications included ventricular lead dislodgment (2) and pocket hematoma (3). Patients with a DC-ICD had less left ventricular function (29% vs 35%, p=0.035) and a higher prevalence of non-ischemic cardiomyopathies (48% vs 28%, p=0.0076). In conclusion, the DC-ICD may have a higher frequency of device- and lead-related major complications.