Implantable defibrillators improve survival in end-stage renal disease: results from a multi-center registry.

BACKGROUND: Small retrospective analyses suggest that end-stage renal disease (ESRD) patients do not obtain as much of a survival benefit from an implantable cardioverter-defibrillator (ICD) as non-ESRD patients do. We aimed to assess the survival effect of an ICD in ESRD patients with left ventricular dysfunction. METHODS: Data from two registries identified ESRD patients with an ICD and ESRD patients with left ventricular dysfunction (defined as ejection fraction <0.35). Cox proportional hazards regression was performed, including certain predefined covariates to assess the effect of an ICD on survival. RESULTS: Overall survival in the full cohort was a median of 4.7 years with 20 deaths in the ICD group and 29 deaths in the no-ICD group. The median survival in the ICD group was 8.0 years and 3.1 years in the no-ICD group. Crude analysis showed a better survival in the ICD group as compared to the no-ICD group (p = 0.016). The multivariable analysis confirmed that the ICD group had significantly less all-cause mortality compared to the no-ICD group (HR: 0.40; 95% CI: 0.19, 0.82; p = 0.013). CONCLUSION: An ICD is associated with a higher survival in ESRD patients with left ventricular dysfunction. This result merits further study in a larger cohort of patients.

Persistent left superior vena cava: a case report and review of literature.

Persistent left superior vena cava is rare but important congenital vascular anomaly. It results when the left superior cardinal vein caudal to the innominate vein fails to regress. It is most commonly observed in isolation but can be associated with other cardiovascular abnormalities including atrial septal defect, bicuspid aortic valve, coarctation of aorta, coronary sinus ostial atresia, and cor triatriatum. The presence of PLSVC can render access to the right side of heart challenging via the left subclavian approach, which is a common site of access utilized when placing pacemakers and Swan-Ganz catheters. Incidental notation of a dilated coronary sinus on echocardiography should raise the suspicion of PLSVC. The diagnosis should be confirmed by saline contrast echocardiography.

Shaft aneurysm of femoropopliteal expanded polytetrafluoroethylene graft treated with a covered stent.

Aneurysm formation is a known complication of native vein or synthetic grafts following peripheral bypass surgery. However, with improvement in the material used for prosthetic grafts, these complications are now uncommon. Open surgery has always been the treatment of choice for aneurysms, but the emergence of percutaneous endovascular intervention has led to a safer and easier way to treat aneurysms. In this article, a unique case of aneurysm in a reinforced expanded polytetrafluoroethylene graft placed 11 years ago during a femoropopliteal bypass surgery in a 77-year-old woman with peripheral arterial disease is presented. The aneurysm was treated percutaneously with a self-expanding covered stent resulting in complete isolation of the aneurysm with no complications encountered.

Statin therapy in the reduction of cardiovascular events in patients undergoing intermediate-risk noncardiac, nonvascular surgery.

BACKGROUND: Hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) reduce perioperative cardiac events in high-risk patients undergoing cardiovascular surgery. However, there is paucity of data on the role of statins in patients undergoing intermediate-risk noncardiac, nonvascular surgery (NCNVS). HYPOTHESIS: Statins are cardioprotective in intermediate-risk NCNVS. METHODS: We identified a retrospective cohort of patients undergoing intermediate risk NCNVS. Our composite end point (CEP) included 30-day all-cause mortality, atrial fibrillation (AF), and nonfatal myocardial infarction (MI). A stepwise logistic regression with adjustment using propensity scores was performed to determine if statin therapy was independently associated with the risk reduction of adverse postoperative cardiovascular outcomes. RESULTS: We identified 752 patients. Seventy-five of them (9.97%) developed composite end points; 10 (1.33%) had in-hospital nonfatal MI, 44 (5.85%) developed AF, and 35 (4.65%) died within 30 days. The 30-day all-cause mortality was 31/478 (6.48%) among statin nonusers vs 4/274 (1.45%) for statin users (P < 0.002). As compared with nonusers, patients on statin therapy had a 5-fold reduced risk of 30-day all-cause mortality. Statin therapy was associated with decreased CEP after adjusting for baseline characteristics, with a propensity score to predict use of statins (odds ratio [OR]: 0.54, 95% confidence interval [CI]: 0.30-0.97, P = 0.039). After further adjustment for propensity score, diabetes mellitus, percutaneous coronary intervention, and prior coronary artery bypass grafting, statin therapy proved beneficial (OR: 0.51, 95% CI: 0.28-0.92, P = 0.026). CONCLUSIONS: Statin use in the perioperative period was associated with a reduction in cardiovascular adverse events and 30-day all-cause mortality in patients undergoing intermediate-risk NCNVS.

Amiodarone - a 'broad spectrum' antiarrhythmic drug.

Amiodarone, an iodinated benzofuran derivative, introduced in 1960's as an anti-anginal agent, emerged as a potent anti-arrhythmic agent by 1970's and is currently one of the most commonly prescribed drugs in US for ventricular and atrial arrhythmias. Although amiodarone is considered a class III anti-arrhythmic agent, it also has class I, II, IV actions, making it a unique and effective anti-arrhythmic agent. Because of its minimal negative inotropic activity and very low rate of pro-arrhythmia, it is considered safe in treating arrhythmias in patients with Coronary Artery Disease and Left ventricular systolic dysfunction. Despite these advantages, long term oral therapy with amiodarone is limited by side effect profile involving various organs like thyroid, lung, heart, liver, skin etc. Though the side effects can be decreased significantly by keeping the maintenance dose at 200 to 300 mg/day, patients on amiodarone should be followed closely. Amiodarone interacts with medications such as Warfarin, Digoxin, Macrolides, Floroquinolones etc., which share Cytochrome P450 metabolic pathway. Hence reducing their doses prior to starting amiodarone is recommended. Amiodarone, a category D drug, is contraindicated in pregnant and breast feeding women. This review discusses the pharmacokinetics of amiodarone, its evolving clinical indications, management of toxicity and drug interactions.

Guillain-Barré Syndrome with asystole requiring permanent pacemaker: a case report.

INTRODUCTION: Guillain-Barré syndrome is an acute demyelinating disorder of the peripheral nervous system that results from an aberrant immune response directed at peripheral nerves. Autonomic abnormalities in Guillain-Barré syndrome are usually transient and reversible. We present a case of Guillain-Barré syndrome requiring a permanent pacemaker in view of persistent symptomatic bradyarrhythmia. CASE PRESENTATION: An 18-year-old Caucasian female presented with bilateral lower limb paraesthesias followed by bilateral progressive leg weakness and difficulty in walking. She reported an episode of an upper respiratory tract infection 3 weeks prior to the onset of her neurological symptoms. Diagnosis of Guillain-Barré syndrome was considered and a lumbar puncture was performed. Cerebrospinal fluid revealed albuminocytologic dissociation (increased protein but normal white blood cell count) suggestive of Guillain-Barré syndrome and hence an intravenous immunoglobulin G infusion was started. Within 48 hours, she progressed to complete flaccid quadriparesis with involvement of respiratory muscles requiring mechanical ventilatory support. Whist in the intensive care unit, she developed multiple episodes of bradycardia and asystole requiring a temporary pacemaker. In view of the persistent requirement for the temporary pacemaker for more than 5 days, she received a permanent pacemaker. She returned for follow-up three months after discharge with an intermittent need for ventricular pacing. CONCLUSION: Guillain-Barré syndrome can result in permanent damage to the cardiac conduction system. Patients with multiple episodes of bradycardia and asystole in the setting of Guillain-Barré syndrome should be evaluated and considered as potential candidates for permanent pacemaker implantation.

Coronary artery fistula: a case series with review of the literature.

Coronary artery fistula (CAF) is an anomalous connection between a coronary artery and a major vessel or cardiac chamber. Most of the coronary fistulas are discovered incidentally during angiographic evaluation for coronary vascular disorder. The management of CAF is complicated and recommendations are based on anecdotal cases or very small retrospective series. We present three cases of CAF, two of which were symptomatic due to hemodynamically significant coronary steal phenomenon. They underwent successful transcatheter coil embolization, leading to resolution of their symptoms. Percutaneous closure offers a safe and effective way for the management of symptomatic patients. CAFs are rare cardiac anomalies but can give rise to a variety of symptoms because of their hemodynamic consequences or complications. They should be part of cardiac differential diagnosis particularly in patients without other risk factors. Correction of CAF is indicated if the patients are symptomatic or if other secondary complications develop.

Predictors of hemodynamic compromise with propofol during defibrillator implantation: a single center experience.

BACKGROUND: Intra-operative hypotension has been reported in cardiac resynchronization therapy defibrillator (CRT-D) clinical trials but this phenomenon is not well characterized. The purpose of this study was to understand the frequency and determinants of intra-operative hypotension in patients undergoing defibrillator implantations. METHODS: We retrospectively reviewed clinical data of all CRT-D implantations over a 21-month period. We compared a randomly selected contemporaneous group undergoing implantable cardiac defibrillator (ICD) implantations as a reference group. Procedure protocol involved intra-arterial blood pressure monitoring throughout the case. Lidocaine (1%) was routinely used along with propofol for sedation in all patients. Procedure time was defined as the time from initial administration of lidocaine for arterial line access, to completion of defibrillator pocket closure. Cumulative dose of propofol was calculated in each patient. Hypotension was defined as a fall in the systolic blood pressure of >or=30% from baseline or a systolic blood pressure of 3 min. CRT-D and ICD patients were divided into hypotensive and non-hypotensive subsets. RESULTS: The incidence of hypotension in the CRT-D group (N = 100) was 56%, as compared to 40% in the ICD group (N = 97). The mean duration of procedure in the CRT-D group was 114 +/- 95 min in the hypotensive subset versus 69 +/- 31.9 min in the non-hypotensive subset (p = 0.0015). The mean NYHA class in the hypotensive subset of the CRT-D group was 2.85 +/- 1.2 vs 2.2 +/- 1.5 in the non-hypotensive subset (p = 0.0179). Cumulative dose of propofol in the hypotensive subset of the CRT-D group was 386 +/- 22 mg, while that in the non hypotensive subset was 238.3 +/- 17 mg (p < 0.0001). Creatinine clearance in the hypotensive subset of the CRT-D group was 63.8 +/- 12.8 ml/min, while that in the non-hypotensive subset was 78.7 +/- 23.5 ml/min (p = 0.003). Patients in the CRT-D group who developed hypotension had a lower left ventricular ejection fraction of 21.1 +/- 10.2% versus 29 +/- 14.8% in the non-hypotensive subset (p = 0.0035). CONCLUSIONS: Hypotension is a common occurrence during defibrillator implantation under conscious sedation. Risk factors for significant hypotension include: higher NYHA class, lower left ventricular ejection fraction, lower creatinine clearance, higher doses of propofol and longer procedure times.

Interferon-ribavirin-associated ischemic colitis.

Interferon-alpha and ribavirin are widely used treatments for chronic hepatitis C. It is believed to be a cytokine made by T lymphocytes upon activation by foreign antigens. Complications of interferon and ribavirin therapy include systemic flulike symptoms, marrow suppression, emotional liability, auto immune reactions (especially auto immune thyroiditis) and miscellaneous side effects such as alopecia, rashes, diarrhea, numbness, and tingling of the extremities. With the possible exception of autoimmune thyroiditis, all these side effects are reversed upon dose lowering or cessation of therapy. We report a case of a 51-year-old man, with no previous history of vascular disease, who developed ischemic colitis after interferon-alpha and ribavirin therapy for chronic hepatitis C. In the literature, there have been only 2 published accounts associating interferon-alpha use with ischemic colitis in 2 patients. This report illustrates a better association of interferon-alpha and ribavirin with ischemic colitis.

Hemodynamic collapse during left ventricular lead implantation.

Hypotension as a procedural complication during cardiac resynchronization therapy (CRT) implantation was reported in the initial randomized clinical trials. However, this phenomenon is not well characterized. We reviewed our CRT implantation experience to better understand this issue. There were 105 patients who underwent left ventricular lead implantation for CRT. Four patients had marked hypotension (systolic blood pressure < or = 50 mmHg) during the procedure. All had a history of hypertension and diabetes mellitus and were pacemaker dependent. Two had normal renal function, one had moderate renal insufficiency, and one was on dialysis. Three patients had ischemic cardiomyopathy. All had left ventricular ejection fraction < or =20% and were in New York Heart Association class III. Propofol and midazolam were used for sedation as standard protocol. Two patients had sudden hypotension when the coronary sinus was being cannulated, and two patients experienced sudden hypotension during left ventricular pacing. Cardiac tamponade as a possible cause was ruled out by echocardiography. We discuss possible mechanisms of sudden hemodynamic collapse during CRT implantation.