Troponin Elevation in Sickle Cell Disease.

OBJECTIVE: Sickle cell disease is associated with cardiovascular abnormalities. Troponin is not typically measured in this population, and thus the significance of abnormal levels of troponin is unknown. We wanted to evaluate the use of troponin and factors that predispose troponin elevation in patients admitted with sickle cell pain crisis (SCPC). METHODS: We reviewed data of consecutive patients admitted to a tertiary care hospital between 2006 and 2011 with a diagnosis of SCPC. Subjects with elevated troponin (ET) (troponin I >0.04 ng/mL) were compared with those with normal troponin (NT) for demographics, risk factors, presence of echocardiography-derived tricuspid regurgitant jet velocity (TRV) ≥3 m/s suggesting pulmonary hypertension, and laboratory tests. The Mann-Whitney U test was used to compare groups. RESULTS: Two hundred eighty-three of 724 patients admitted with SCPC had chest pain. Troponin I was measured in 63 patients: 51 had NT and 12 had ET ranging from 0.06 to 3.42 ng/ml. ET was associated lower hemoglobin (p = 0.02), lower hematocrit (p = 0.02), lower platelet number (p < 0.001), higher LDH (p = 0.012), higher AST levels (p = 0.004), higher bilirubin levels (p = 0.006), and TRV ≥3 m/s (p = 0.028). CONCLUSIONS: Troponin was measured in <10% of patients with SCPC, and 1 out of 5 of them had ET. Troponin elevation was not associated with traditional cardiovascular risk factors but was associated with lower hematocrit, elevated LDH, bilirubin levels, and TRV ≥3 m/s.

Cocaine use does not affect mean platelet volume.

Increased mean platelet volume (MPV) is a marker of platelet activation. Platelet activation with cocaine use is not well studied. We wanted to investigate MPV levels in patients with cocaine-associated chest pain (CACP) as a marker of platelet activation. Retrospectively, MPV of 82 consecutive patients with CACP (group 1) with positive urine drug screen (UDS), without acute myocardial infarction (AMI) (group 1A) and with AMI with elevated troponin (group 1B), were included in the study. The control group (group 2) consisted of 89 consecutive patients admitted during the same time period with acute chest pain (ACP) who had negative UDS and negative cardiac markers with a normal cardiac stress test or normal coronary angiogram. Analysis showed no statistically significant difference of MPV between group 1, 8.46 ± 1.06 fL, versus group 2, 8.7 ± 1.07 fL; p = 0.142; and between group 1A, 8.46 ± 1.05 fL, and group 1B, 8.46 ± 1.09 fL; p = 0.983. By multiple linear regression analysis, MPV was not influenced by cocaine abuse (R = 0.269, R (2) = 0.072, adjusted R (2) = -0.009, p = 0.562). MPV is not elevated in patients with cocaine use even when they had AMI. Further studies may be necessary to investigate the role of platelet activation in patients with cocaine use and chest pain.

Organ-specific protective role of NKT cells in virus-induced inflammatory demyelination and myocarditis depends on mouse strain.

Theiler's murine encephalomyelitis virus (TMEV) can induce demyelination or myocarditis in susceptible mouse strains. A deficiency of NKT cells exacerbated TMEV-induced demyelinating disease (TMEV-IDD) in SJL/J and BALB/c mice. In C57BL/6 background, however, NKT-cell-deficient Jα18 KO mice remained as resistant to TMEV-IDD as wild-type mice. Echocardiography and histology showed that Jα18 KO mice developed more severe myocarditis (greater T cell infiltration and fibrosis) than wild-type mice, suggesting a protective role of NKT cells in myocarditis in C57BL/6 mice. Jα18 KO mice had higher cardiac viral RNA and anti-viral antibody titers, but had lower lymphoproliferation and IL-4 and IL-10 production.

Digoxin Use to Control Ventricular Rate in Patients with Atrial Fibrillation and Heart Failure Is Not Associated with Increased Mortality.

Introduction. Digoxin is used to control ventricular rate in atrial fibrillation (AF). There is conflicting evidence regarding safety of digoxin. We aimed to evaluate the risk of mortality with digoxin use in patients with AF using meta-analyses. Methods. PubMed was searched for studies comparing outcomes of patients with AF taking digoxin versus no digoxin, with or without heart failure (HF). Studies were excluded if they reported only a point estimate of mortality, duplicated patient populations, and/or did not report adjusted hazard ratios (HR). The primary endpoint was all-cause mortality. Adjusted HRs were combined using generic inverse variance and log hazard ratios. A multivariate metaregression model was used to explore heterogeneity in studies. Results. Twelve studies with 321,944 patients were included in the meta-analysis. In all AF patients, irrespective of heart failure status, digoxin is associated with increased all-cause mortality (HR [1.23], 95% confidence interval [CI] 1.16-1.31). However, digoxin is not associated with increased mortality in patients with AF and HF (HR [1.08], 95% CI 0.99-1.18). In AF patients without HF digoxin is associated with increased all-cause mortality (HR [1.38], 95% CI 1.12-1.71). Conclusion. In patients with AF and HF, digoxin use is not associated with an increased risk of all-cause mortality when used for rate control.

Distinct kinetics of viral replication, T cell infiltration, and fibrosis in three phases of myocarditis following Theiler's virus infection.

We established a novel model of myocarditis induced with Theiler's murine encephalomyelitis virus (TMEV), which has been used as a viral model for multiple sclerosis and seizure/epilepsy. Following TMEV infection, C3H mice developed severe myocarditis with T cell infiltration, while C57BL/6 mice had mild lesions and SJL/J mice had no inflammation in the heart. In C3H mice, myocarditis was divided into three phases: acute viral, subacute immune, and chronic fibrotic phases. Using toll-like receptor (TLR) 4-deficient C3H mice, we found that interleukin (IL)-6, IL-17, TLR4, and anti-viral immune responses were associated with myocarditis susceptibility.

Treatment of methadone-induced torsades de pointes with lidocaine.

Methadone maintenance treatment (MMT) is commonly used for chronic pain control and for substitution in heroin addicts undergoing rehabilitation. Methadone is known to prolong QT interval and sometimes cause torsade de pointes (TdP) and ventricular fibrillation (VF). Treatment of TdP by antiarrhythmic drugs that prolong QT interval may worsen TdP. To our knowledge, worsening of methadone-induced TdP by amiodarone has not been reported before. We describe here a case of methadone-induced TdP that deteriorated into ventricular fibrillation upon treatment with intravenous (IV) amiodarone and resolved after discontinuation of amiodarone and treatment with IV magnesium, potassium, and lidocaine.

Transthoracic echocardiogram is a useful tool in the hemodynamic assessment of patients with chest trauma.

INTRODUCTION: The utility of transthoracic echocardiogram (TTE) in patients on the trauma service is not well defined. The aim of this study was to evaluate the frequency of abnormal echocardiographic findings that would aid in the assessment and management of cardiovascular hemodynamics in patients with chest trauma. METHODS: A retrospective analysis of all patients who had a TTE on the trauma service at a level 1 trauma center during a 12-month period was performed. RESULTS: There were 94 patients in the study. TTE was performed after cardiac surgery in 5 patients. One of the 5 patients with prior cardiac surgery was excluded from the study because of poor quality images, and each of the remaining 4 patients showed significant TTE abnormalities. Of the 89 patients without prior cardiac surgery, 38 (43%) had significant TTE findings although 32 (84%) of them had no known history of cardiac abnormalities. A decreased left ventricular ejection fraction (<50%) was found in 18% of all patients, and half of them were hemodynamically unstable. Significant valvular regurgitation or stenosis was found in 31 patients, pulmonary hypertension in 25 patients, left ventricular wall motion abnormalities in 12 patients and pericardial effusion in 11 patients. CONCLUSION: Significant echocardiographic abnormalities are detected by TTE in patients with chest trauma. Such findings can be used in the hemodynamic assessment and management of unstable patients during their hospitalization and in planning long-term follow-up and management of these patients after discharge from the hospital.

Platypnea-orthodeoxia syndrome: a diagnostic challenge.

Platypnea-orthodeoxia (P-O) syndrome is an underdiagnosed condition characterized by dyspnea and deoxygenation accompanying a change from a recumbent to an upright position. It is caused by increased right-to-left shunting of blood on assuming an upright position. The diagnosis of this shunt is often challenging. A case where a diagnosis was missed despite performing a tilt transesophageal echocardiogram with bubble study and a technetium labeled macroaggregated albumin scan is presented. However, a large patent foramen ovale (PFO) was found on autopsy. A brief overview of the diagnostic workup and management of this condition along with methods to increase the sensitivity of diagnostic tests is discussed.

Poor outcome of indigent patients with peripartum cardiomyopathy in the United States.

OBJECTIVE: Peripartum cardiomyopathy (PPCM) patients from Haiti and South Africa have poor survival and poor left ventricular (LV) function recovery compared with patients from the United States. There are no reported studies of PPCM among the African American population in the United States. We evaluated the prognosis of PPCM in a mostly African American population. STUDY DESIGN: We analyzed the clinical and echocardiographic data of 44 (39 African American) patients with PPCM over an 11 year period (1992-2003). RESULTS: Thirty-nine patients were indigent and 5 had health insurance. During a mean follow-up of 24.0 (range, 0.1-264) months, 7 (15.9%) patients died and LV function returned to normal in 14 (35%). CONCLUSION: LV function recovery and survival rates of PPCM patients observed in our study are similar to those reported from Haiti and South Africa and different from what is generally accepted in the United States.

Electrocardiographic abnormalities in patients with acute burn injuries.

OBJECTIVE: To determine the incidence and types of electrocardiographic (ECG) abnormalities in patients admitted with acute burn injuries and correlate them with the degree and the extent of burn injuries. METHODS: Retrospective analysis of 192 patients admitted to the burn unit was performed. Thirty-four patients met the inclusion criteria of having a 12-lead ECG performed on admission and at least one more time during their stay. RESULTS: There were 26 men and 8 women. The average age of patients was 53.4 +/- 17.5 years. The average degree of burn was 2.4 +/- 0.6 and the average body surface area (BSA) involved was 12.8 +/- 11.8%. There were 18 patients (53%) with ECG abnormalities. Five patients had sinus tachycardia, including two with premature atrial complexes (PACs) and one with ST-T abnormality. Three patients had premature ventricular complexes (PVCs), including one with a paced atrial rhythm and one with a prolonged QT interval. Right bundle branch block was present in two patients, and low voltage QRS was present in one. Atrial fibrillation was present in two patients, including one with ST-T abnormality due to digitalis effect. Four patients had a prolonged QT interval as the sole abnormality. One patient had left ventricular hypertrophy, an old inferior myocardial infarct, PACs, and non-specific ST-T wave abnormality. CONCLUSIONS: In patients with acute burn injuries sinus tachycardia and a prolonged QT interval were the most common ECG abnormalities. There was no correlation between the extent of burn injuries and observed ECG abnormalities. No patient had a life threatening arrhythmia, and all patients had a good outcome.

Therapies to increase high-density lipoprotein cholesterol and their effect on cardiovascular outcomes and regression of atherosclerosis.

Epidemiological studies have shown that decreased level of high-density lipoprotein (HDL) cholesterol (C) is an independent inverse predictor of coronary artery disease (CAD) even in patients with normal levels of low-density lipoprotein (LDL)-C. There is an abundance of evidence in favor of statins and aggressive LDL-C lowering therapy for both primary and secondary prevention of CAD. In contrast, the evidence for reduction of CAD risk with HDL-C raising therapy is relatively thin, partly due to the paucity of effective and safe drugs for increasing HDL-C level. However, there are emerging new therapies for raising HDL-C level and growing evidence in favor of pharmacologic therapies to raise HDL-C level. We present in this article a review of pharmacologic therapies that are currently available to increase HDL-C level, their safety and efficacy in relation to cardiovascular endpoints.

Control of cardiovascular risk factors and use of aspirin in diabetic patients remain elusive.

OBJECTIVES: Type 2 diabetics are at higher risk for cardiovascular disease. To reduce this risk, the American Diabetes Association recommends traditional cardiovascular disease risk factor modification, reducing hemoglobin A1c (HbA1c), and the use of aspirin for patients over 30 years of age. The goal of this study was to analyze how well these goals were achieved in type 2 diabetics. METHODS: Patients with type 2 diabetes from July 2004 to June 2005 were included. Data were collected on demographics, preexisting coronary artery disease (CAD), blood pressure control, HbA1c, low-density lipoprotein cholesterol level, and microalbuminuria. RESULTS: One hundred thirty-nine patients were included (18% had CAD). Blood pressure was controlled in 46.04% of patients; 41.72% reached target HbA1c; 47.48% reached target low-density lipoprotein cholesterol; and 43.88% had microalbuminuria. No significant difference was noted between diabetics with or without CAD. Aspirin was used in 64% of patients with CAD and in 28.15% patients without CAD. CONCLUSIONS: Optimal cardiovascular risk modification was achieved in less than 50% of type 2 diabetics. Aspirin remains underused for primary prevention. These results highlight the continued difficulties in achieving control of diabetes to the extent recommended by American Diabetes Association guidelines.

In-stent stenosis: potential role of increased oxidative stress and glutathione-linked detoxification mechanisms.

This study was designed to determine whether red-cell oxidative stress status and antioxidant enzyme levels can serve as markers in patients predisposed to in-stent stenosis. Blood was collected from patient groups undergoing coronary angiography for chest pain evaluation, namely, group A (without coronary artery disease), group B (previous coronary stents without in-stent stenosis), and group C (previous coronary stents with in-stent stenosis). Thiobarbituric acid reactive substances (measure of lipid peroxidation), glutathione-linked detoxification enzymes, catalase, and superoxide dismutase were determined. Compared with group A, patients in group C showed increased lipid peroxidation products and glutathione-S-transferase but decreased glutathione peroxidase and glutathione reductase activities. Results in group B patients were intermediate between those of groups A and C with significant decreases in glutathione peroxidase versus controls. In-stent stenosis is associated with significant increase in lipid peroxidation and attenuated glutathione-linked detoxification enzymes, consistent with oxidative stress.

Effects of electromagnetic interference on implanted cardiac devices and their management.

Potential interference between implanted cardiac devices such as pacemakers and implantable cardioverter-defibrillators and electromagnetic fields is an important concern for physicians taking care of patients with pacemakers and implantable cardioverter-defibrillators. There are many sources of electromagnetic interference (EMI); however, only a small number of these cause significant problems that need attention. Regardless of its source, EMI is of greater concern for a patient who is dependent on paced rhythm because inhibition of the pacemaker by EMI may produce ventricular standstill. It is important that cardiologists, internists, emergency medicine, critical care physicians, and anesthesiologists be aware of how EMI can affect the function of implanted cardiac devices so that appropriate treatment can be rendered and preventive measures instituted.

Gender differences in selection of pacemakers: a single-center study.

BACKGROUND: Previous studies have reported gender differences in pacemaker selection. OBJECTIVE: This study aimed to assess gender-related differences in pacemaker mode selection in patients undergoing their first implantation. METHODS: A retrospective analysis was undertaken from a single-center database of pacemaker implants during the years 2001 to 2003. Univariate and multivariate analyses were used to compare pacemaker mode selection adjusted for any significant difference between the sexes. RESULTS: A total of 274 pacemakers were implanted during the study period, 259 of which formed the basis of this study. Of the patients receiving pacemakers, 132 were male and 127 were female. The majority of patients (144 [55.6%]) had sick sinus syndrome as their indication for receiving a pacemaker, followed by complete heart block (75 [29.0%]), and second-degree or high-grade atrio-ventricular block (36 [13.9%]). Four (1.5%) patients had hypersensitive carotid sinus syndrome. The mean (SD) age of patients was 61.35 (15) years. Most (155 [59.8%]) patients were younger than age 65, and the women were significantly older than the men (P = 0.004). Atrial fibrillation (AF) was present in 53 (20.5%) patients. Dual-chamber (DDD) pacemakers were implanted in 196 (75.7%) patients, and single-chamber ventricular pacemakers in 63 (24.3%) patients. Significantly more DDD pacemakers were implanted in patients aged <65 years compared with those aged > or =65 years (P < 0.01). This difference was, however, primarily due to the higher rate of AF in the older patients versus patients aged <65 years. Although the rate of DDD implantations was observed to be higher among women (101/127 [79.5%]) compared with men (95/132 [72.0%]), the rate difference was nonsignificant, even when adjusted for the significant age difference between the sexes. Furthermore, DDD selection was independent of patients' health insurance status. CONCLUSIONS: We found no significant difference in pacemaker mode selection between male and female patients. However, we did find that patients aged <65 years were more likely to have DDD pacemakers implanted compared with older patients. This age-dependent difference was primarily due to the higher prevalence of AF in the older age group versus the younger patients. Key words: pacemaker implant gender difference gender and pacemaker selection.

Comparison of intracoronary vs. intravenous administration of abciximab in coronary stenting.

There have been animal and human studies looking at intracoronary (IC) use of abciximab with good short-term clinical outcomes. There exists no data comparing intracoronary with intravenous (IV) administration of abciximab beyond 30 days. We compared the clinical outcomes between the IC (n = 101) and IV (n = 72) group of patients. Patients who had coronary stenting and received abciximab were included in the study. All the patients received the standard systemic bolus dose of abciximab 0.25 mg/kg either via the IC or IV route, followed by a 12-hr IV infusion at 0.125 microg/kg/min. The 6-month composite endpoint of death or myocardial infarction was slightly higher in the IV (13.9%) than in the IC group (5.9%; P = 0.04). The frequency of bleeding complications was similar in both groups. The IC bolus route of abciximab may be superior to the intravenous route. Prospective randomized trials are warranted to validate these findings.

Outcomes of coronary artery bypass grafting in patients with a history of illicit drug use.

To date, no studies have been conducted on the effects of illicit drug use in patients with ischemic heart disease treated with coronary artery bypass grafting. Our retrospective study suggests that current illicit drug use is a significant predictor of cardiovascular complications in the first 6 months after coronary artery bypass grafting.