Sandeep K. Goyal

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.

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.

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.

Amiodarone - a 'broad spectrum' antiarrhythmic drug.

Amiodarone, an iodinated benzofuran derivative, introduced in 1960s as an anti-anginal agent, emerged as a potent anti-arrhythmic agent by 1970s 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.

Original ResearchCardiovascular DiseaseRisk of Serious Atrial Fibrillation and Stroke With Use of Bisphosphonates: Evidence From a Meta-analysis

BACKGROUND Clinical studies have suggested an association between bisphosphonate use and the onset of atrial fibrillation (AF). However, data on the risk of developing AF, stroke, and cardiovascular mortality with the use of bisphosphonate are conflicting. The objective of this study was to evaluate the risk of serious AF (events that required hospital admission), stroke, and cardiovascular mortality with the use of bisphosphonates through a systematic review of the literature. METHODS We searched the PubMed, CENTRAL, and EMBASE databases for observational studies and randomized controlled trials (RCTs) on the use of bisphosphonates from 1966 to April 2012 that reported the number of patients who developed serious AF, stroke, and cardiovascular mortality at follow-up. The random-effects Mantel-Haenszel test was used to evaluate relative risk-adverse cardiovascular outcomes with the use of bisphosphonates. RESULTS Six observational studies (n = 149,856) and six RCTs (n = 41,375) were included for analysis. On pooling observational studies, there was an increased risk of AF (OR, 1.27; 95% CI, 1.16-1.39) among bisphosphonate users. Further, analysis of RCTs revealed a statistically significant increase in the risk of serious AF (OR, 1.40; 95% CI, 1.02-1.93) and no increase in the risk of stroke (OR, 1.07; 95% CI, 0.85-1.34) or cardiovascular mortality (OR, 0.92; 95% CI, 0.68-1.26) with the use of bisphosphonates. CONCLUSIONS Evidence from RCTs and observational studies suggests a significantly increased risk of AF requiring hospitalization, but no increase in risk of stroke or cardiovascular mortality, with the use of bisphosphonate.

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

IntroductionGuillain-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 PresentationAn 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.ConclusionGuillain-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.

RISK OF SERIOUS ATRIAL FIBRILLATION AND STROKE WITH USE OF BISPHOSPHONATES: EVIDENCE FROM A META-ANALYSIS

Background: Clinical studies have suggested an association between bisphosphonate use and the onset of atrial fi brillation (AF). However, data on the risk of developing AF, stroke, and cardiovascular mortality with the use of bisphosphonate are confl icting. The objective of this study was to evaluate the risk of serious AF (events that required hospital admission), stroke, and cardiovascular mortality with the use of bisphosphonates through a systematic review of the literature. Methods: We searched the PubMed, CENTRAL, and EMBASE databases for observational studies and randomized controlled trials (RCTs) on the use of bisphosphonates from 1966 to April 2012 that reported the number of patients who developed serious AF, stroke, and cardiovascular mortality at follow-up. The random-effects Mantel-Haenszel test was used to evaluate relative riskadverse cardiovascular outcomes with the use of bisphosphonates. Results: Six observational studies (n 5 149,856) and six RCTs (n 5 41,375) were included for analysis. On pooling observational studies, there was an increased risk of AF (OR, 1.27; 95% CI, 1.16-1.39) among bisphosphonate users. Further, analysis of RCTs revealed a statistically signifi cant increase in the risk of serious AF (OR, 1.40; 95% CI, 1.02-1.93) and no increase in the risk of stroke (OR, 1.07; 95% CI, 0.85-1.34) or cardiovascular mortality (OR, 0.92; 95% CI, 0.68-1.26) with the use of bisphosphonates. Conclusions: Evidence from RCTs and observational studies suggests a signifi cantly increased risk of AF requiring hospitalization, but no increase in risk of stroke or cardiovascular mortality, with the use of bisphosphonate.

Noninvasive Risk Assessment Early After a Myocardial Infarction: Are We Looking at the Right Indicators?

Exner et al. ([1][1]) looked at the role of combined assessment of autonomic tone plus cardiac electrical substrate as markers of predicting long-term mortality in evaluating 322 patients who survived myocardial infarction (MI) but with left ventricular (LV) dysfunction. We have 3 concerns about

Adverse Events Associated With Stopping Clopidogrel After Acute Coronary Syndrome

tients with acute MI, it is unlikely to be a sufficient explanation of the link between glucose and mortality in acute MI given that this relationship is even stronger in nondiabetic than in diabetic patients. Selker et al also note that our results showing increased mortality among patients with acute MI with postrandomization potassium levels of 5 mmol/L or greater are counter to studies reporting that low potassium levels increase the risk of sudden cardiac death. However, most of these studies were small, were conducted in the 1980s before the widespread use of reperfusion therapy, and focused primarily on early in-hospital sudden cardiac death rather than postdischarge total mortality. One other study has reported no association between hypokalemia and mortality. Dr Chaudhuri and colleagues suggest that insulin may have been beneficial in patients in whom normoglycemia was maintained. We did not find that GIK was beneficial in patients with postrandomization glucose levels in the normoglycemic range ( 126 mg/dL) (TABLE). However, we agree that the approach of giving fixed-dose GIK to alter cardiac metabolism during ischemia is different from dosing insulin to achieve glucose normalization in hyperglycemic patients with acute MI, and this latter strategy merits investigation in clinical trials.