Kul Aggarwal

Obesity and heart failure: epidemiology, pathophysiology, clinical manifestations, and management

Obesity is a risk factor for heart failure (HF) in both men and women. The mortality risk of overweight and class I and II obese adults with HF is lower than that of normal weight or underweight adults with HF of comparable severity, a phenomenon referred to as the obesity paradox. Severe obesity produces hemodynamic alterations that predispose to changes in cardiac morphology and ventricular function, which may lead to the development of HF. The presence of systemic hypertension, sleep apnea, and hypoventilation, comorbidities that occur commonly with severe obesity, may contribute to HF in such patients. The resultant syndrome is known as obesity cardiomyopathy. Substantial weight loss in severely obese persons is capable of reversing most obesity-related abnormalities of cardiac performance and morphology and improving the clinical manifestations of obesity cardiomyopathy.

Dynamic Left Ventricular Outflow Tract Obstruction in Acute Myocardial Infarction With Shock Cause, Effect, and Coincidence

Case presentation: A 70-year-old white woman with a prior history of tobacco abuse, emphysema, and recent pneumonia presented to an outside emergency room with brief episodes of dull chest pressure recurring over 5 days. Because the current episode was not relieved after 4 hours, and because her ECG showed ST elevation up to 3 mm in V2 through V6, she was given heparin and nitroglycerin infusions and was transferred to the University of Missouri. On admission to our hospital, she was pain-free with stable vital signs. Her examination was remarkable for a grade 2/6 systolic ejection murmur in the left third intercostal space. An ECG showed Q waves in V1 through V3. Echocardiography revealed significant left ventricular (LV) dysfunction, ejection fraction of 35% with systolic anterior motion (SAM) of the anterior mitral leaflet, and moderate mitral regurgitation (MR; Figure 1). LV outflow tract (LVOT) gradients were not quantified owing to MR Doppler contamination. Her maximum troponin was 5 ng/mL, and brain natriuretic peptide was 190 pg/mL. Catheterization showed normal coronaries with anteroapical akinesia and LV dysfunction with an ejection fraction of 30%. Figure 1. Apical 4-chamber view showing SAM of anterior mitral leaflet. LA indicates left atrium. The patient became hypotensive after catheterization, with systolic pressures between 70 and 85 mm Hg. Dopamine infusion did not improve blood pressure, and the murmur increased to grade 3/6 intensity. Atrial fibrillation developed with a ventricular rate of 150 bpm. Dopamine was discontinued, and intravenous amiodarone converted the …

RESEARCH FROM THE UNIVERSITY OF ALABAMA AT BIRMINGHAM: Patent Foramen Ovale in a Large Population of Ischemic Stroke Patients: Diagnosis, Age Distribution, Gender, and Race

Background: Patent foramen ovale (PFO) is a well‐recognized risk factor for ischemic strokes. The true prevalence of PFO among stroke patients is still under debate. Transesophageal echocardiography (TEE) is the “gold standard” in diagnosing PFO but the physiology requires right‐to‐left atrial shunting. In this report, we evaluate the prevalence of PFO in a diverse group of ischemic stroke patients studied by TEE. Methods: TEE of 1,663 ischemic stroke patients were reviewed for cardiac source of embolism, including PFO and atrial septal aneurysm (ASA). Agitated saline bubble injection was performed to look for right to left atrial shunting. Success of maneuvers to elevate right atrial pressure (RAP) was noted by looking at the atrial septal bulge. Results: Among 1,435 ischemic stroke patients analyzed, the presence or absence of PFO could not be determined in 32.1% because bulging of the septum could not be demonstrated in patients with negative contrast study despite aggressive maneuvers to elevate RAP. Of the remaining 974 patients, 294 patients (30.2%) had a PFO. The mean age was 61.5 years in both groups, with a bimodal distribution of PFO and the highest prevalence occurring in ≤30‐year‐old group. Prevalence of PFO was similar in men (32.4%) and women (28.15%, P = 0.15); and in Caucasian (32.1%) and African American (27.7%; P = 0.15). ASA was present in 2.02% and hypermobile septum in 2.49% of the 1,435 patients. PFO was seen in 79.3% of the patients with ASA. Conclusion: Successful elevation of RAP cannot be achieved in a significant number of patients undergoing TEE and determination of PFO may be difficult. In our series, the true prevalence of PFO among ischemic stroke patients was 30.2% taking into account only those patients who showed no shunting despite bulging of the atrium septum into the left atrium (PFO absent group) during the contrast study. There was no gender or racial difference in the prevalence of PFO, but there was a bimodal distribution in prevalence with age.

Pharmacological and Non Pharmacological Strategies in the Management of Coronary Artery Disease and Chronic Kidney Disease

Patients with advanced chronic kidney disease (CKD), including those treated with dialysis, are at high risk for the development of cardiovascular disease (CVD). CVD accounts for 45-50% of deaths among dialysis patients. Therapy of acute and chronic coronary heart disease (CHD) that is effective in the general population is frequently less effective in patients with advanced CKD. Drug therapy in such patients may require dose modification in some cases. Oral anti-platelet drugs are less effective in those with advanced CKD than in persons with normal or near normal renal function. The intravenous antiplatelet drugs eptifibatide and tirofiban both require dose reductions in patients with advanced CKD. Enoxaparin requires dose reduction in early stage CKD and is contraindicated in hemodialysis patients. Unfractionated heparin and warfarin maybe used without dose adjustment in CKD patients. Atenolol, acetbutolol and nadolol may require dose adjustments in CKD. Metoprolol and carvedilol do not. Calcium channel blockers and nitrates do not require dose adjustment, whereas ranolazine does. Angiotensin converting enzyme inhibitors and angiotensin receptor blockers may safely be used in CKD patients with close observation for hyperkalemia. The safety of spironolactone in such patients is questionable. Statins are less effective in reducing cardiovascular complication in CKD patients and their initiation is not recommended in dialysis patients. Coronary artery bypass grafting is associated with higher short-term mortality, but better long-term morbidity and mortality than percutaneous coronary interventions in patients with advanced CKD with non-ST segment ACS and chronic CHD.

Heart Failure and Obesity in Adults: Pathophysiology, Clinical Manifestations and Management

Obesity is both a risk factor and a direct cause of heart failure (HF) in adults. Severe obesity produces hemodynamic alterations that predispose to changes in left ventricular morphology and function, which, over time, may lend to the development of HF (obesity cardiomyopathy). Certain neurohormonal and metabolic abnormalities as well as cardiovascular co-morbidities may facilitate this process. Substantial purposeful weight loss is capable of reversing most of the alterations in cardiac performance and morphology and may improve functional capacity and quality of life in patents with obesity cardiomyopathy.

Dobutamine stress echocardiography Doppler estimation of cardiac diastolic function: a simultaneous catheterization correlation study.

Background: Doppler echocardiography using the ratio of early diastolic transmitral velocity to early diastolic mitral annular tissue velocity (E/E′) is routinely used to evaluate left ventricular (LV) filling pressures at rest. We tested the hypothesis that measurement of E/E′ in patients undergoing dobutamine stress echocardiography (DSE) will detect changes in LV filling pressures. Methods: In this prospective study, 16 patients with normal LV ejection fraction and normal coronary arteries by angiography underwent a standard DSE protocol with simultaneous LV filling pressure monitoring with a fluid filled pigtail catheter. Doppler echocardiographic assessment of LV diastolic function was performed using E/E′ at rest and during DSE. Results: The average age of the study participants was 57 ± 8 years. Average heart rate was 61 ± 11 bpm at baseline and 141 ± 12 bpm at peak stress. LV mean diastolic pressure decreased from 12.3 ± 2.6 mmHg at baseline to 9.0 ± 2.3 mmHg at peak stress (P = 0.0001). Baseline E/E′ at the septum and lateral annulus were 8.7 ± 2.2 and 7.5 ± 1.9 and during peak stress were 8.3 ± 3.1 and 7.9 ± 3.5, respectively. There was no significant change in E/E′ at either the septum or the lateral annulus (P = 0.55, P = 0.66). There was no significant correlation between LV mean diastolic pressure and E/E′ with dobutamine stress. Conclusions: In patients with normal LV ejection fraction and no significant coronary artery disease undergoing DSE, the ratio of early diastolic transmitral velocity to early diastolic tissue velocity (E/E′) at peak stress with dobutamine does not predict changes in LV filling pressures. (Echocardiography 2011;28:442‐447)

How Does Volume Status Affect BNP and Troponin Levels as Markers of Cardiovascular Status in Peritoneal Dialysis

Cardiac biomarkers such as brain natriuretic peptide, amino-terminal pro-B-type natriuretic peptide (NT-proBNP), and cardiac troponin provide information on cardiovascular morbidity and mortality in patients with normal renal function. In a considerable number of chronic hemodialysis patients, both biomarkers-NT-proBNP and troponin-are elevated despite the absence of cardiac ischemia. The elevation of cardiac biomarkers in chronic hemodialysis patients is of prognostic value with respect to cardiovascular morbidity and mortality. Furthermore, they can serve as tools for volume assessment for optimization of the fluid management aspect of dialysis. However, the association of both these markers in peritoneal dialysis is not clear. Therefore, the authors reviewed the literature to examine the role of these markers in peritoneal dialysis patients both as prognostic indicators as well as tools for volume assessment.

Role of transesophageal echocardiography in detecting implantable cardioverter defibrillator lead infection.

Implantable cardioverter defibrillator (ICD) lead infection is a rare condition with reported incidence of 0.2% to 16%. It usually presents with persistent bacteremia or fever of unknown origin and requires high clinical suspicion for diagnosis. Whenever ICD lead infection is suspected, transesophageal echocardiography is the diagnostic technique of choice for detection and characterization of the lesions. Lead infections are extremely difficult to manage conservatively and surgical removal of the entire defibrillator system is recommended along with antimicrobial therapy. We describe a case of recurrent staphylococci bacteremia due to an ICD lead infection in a patient with arrhythmogenic right ventricular dysplasia. (ECHOCARDIOGRAPHY, Volume 20, April 2003)

Percutaneous coronary intervention and the use of glycoprotein IIb/IIIa inhibitors in patients with chronic kidney disease on dialysis: a single center experience.

Patients on dialysis constitute a major healthcare burden with high prevalence of coronary artery disease frequently requiring coronary revascularization. Prior studies have reported high complications rates with revascularization in patients on dialysis. However, information on the use glycoprotein and direct thrombin inhibitors in this patient population undergoing percutaneous revascularization is limited. We retrospectively analyzed the procedural success and in‐hospital outcomes of percutaneous coronary revascularization in 56 consecutive patients on dialysis compared with 524 patients without renal failure, between January 2001 and August 2007 at our facility. Additionally, we also analyzed the off‐label use of glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitors during revascularization in this high‐risk group of patients to evaluate for possible increased bleeding complications. In the study group, 7 interventions were performed on peritoneal dialysis and 49 on hemodialysis patients. Sixty‐one percent of these patients had diabetes mellitus. A total of 72 lesions were intervened upon; 12 underwent angioplasty and 60 underwent stenting. Four of 72 interventions were not successful, giving a procedural success rate of 94%. There were 6 immediate complications (10.7%), but no deaths. Thirty‐two patients (57%) received GP IIb/IIIa inhibitors while direct thrombin inhibitors were used during percutaneous coronary intervention in 11(20%) patients. There were no bleeding complications with use of either GP IIb/IIIa inhibitors or direct thrombin inhibitors. In our experience, percutaneous coronary intervention has high procedural success in dialysis patients and concomitant use of GP IIb/IIIa inhibitors is not associated with any major bleeding complications, making this a feasible, safe and effective revascularization option for patients on dialysis; however, this merits further study in a randomized prospective trial.

Structural myocardial involvement in adult patients with type 1 myotonic dystrophy

Myotonic dystrophy type 1 (DM1) is the commonest muscular dystrophy in adults, affecting multiple organs in addition to skeletal muscles. Cardiac conduction system abnormalities are well recognized as an important component of DM1 phenotype; however, primary structural myocardial abnormalities, which may predispose these patients to congestive heart failure, are not as well characterized. We reviewed the retrospective analysis of the clinical and echocardiographic findings in adult patients with DM1. Among 27 patients (16 male; age 19–61 years) with DM1, the echocardiogram (ECHAO) was abnormal in 10 (37%) including one of 6 patients (16%) with congenital myotonic dystrophy. Reduced left ventricular ejection fraction (LVEF ≤50%) was noted in 5, diastolic dysfunction in 4, left atrial dilatation in 3, left ventricular hypertrophy in 2, apical hypokinesia in 1 and mitral valve prolapse in 3 patients. One patient had paradoxical septal movement in the setting of left bundle branch block. Echocardiographic abnormalities significantly correlated with older age; however, patients with systolic dysfunction on echocardiogram ranged in age from 27 to 52 years including 2 patients aged 27 and 34 years. We can conclude that echocardiographic abnormalities are frequent in adult patients with DM1. The incidence is similar in the classical and congenital type of DM1. Overall, echocardiographic abnormalities in DM1 correlate with increasing age; however, reduced LVEF is observed even at young age. Cardiac assessment and monitoring in adult patients with DM1 should include evaluation for primary myocardial involvement.