Faculty Bibliography

BACKGROUND: Left ventricular (LV) outflow tract obstruction (LVOTO) is most commonly seen in patients with hypertrophic cardiomyopathy. Postexercise dynamic LVOTO (DLVOTO) has been infrequently identified in symptomatic patients without LV hypertrophy, and its pathophysiology is not well established. The aim of this study was to identify echocardiographic abnormalities that might explain the dynamic development of systolic anterior motion, mitral-septal contact, and LVOTO in these patients. METHODS: Patients with DLVOTO and normal wall thickness were compared with 20 age-matched and gender-matched controls with normal stress echocardiographic findings. Two other groups were also compared: patients with DLVOTO and mild segmental hypertrophy (segmental wall thickness /=5 mm. CONCLUSIONS: DLVOTO after exercise can occur in the absence of LV hypertrophy and may be associated with high gradients and cardiac symptoms. Elongated, redundant mitral valve leaflets with anterior position of the papillary muscles appear to cause the postexercise obstruction.

Patients with coexisting hypertrophic cardiomyopathy (HC) and hypertension present diagnostic and therapeutic dilemmas. A retrospective cohort study of patients with HC with coexisting hypertension referred to a specialized HC program was conducted. HC and hypertension were confirmed by strict criteria. Echocardiographic data were reviewed for peak instantaneous left ventricular outflow tract gradients, at rest and with provocation. Symptom control, left ventricular outflow tract gradients, and hypertension control were compared between the first and last visits. One hundred fifteen patients (94 obstructed and 21 nonobstructed) met the eligibility criteria for the study and were included in the analysis, with the mean follow-up duration of 36 months. Because of the treatment strategy, there was a significant decrease in the number of patients treated with direct vasodilators and an increase in the use of beta blockers and disopyramide. Twenty-one obstructed patients (22%) required septal reduction therapy. Overall, in obstructed patients, peak instantaneous left ventricular outflow tract gradient at rest decreased from 48 to 14 mm Hg (p <0.01), which was accompanied by significant improvement in functional class (2.4 vs 1.8, p <0.01). The prevalence of uncontrolled hypertension decreased from 56% at the initial visit to 37% at the last visit (p = 0.01). The cohort had a low rate of adverse cardiovascular outcomes such as death, acute coronary syndromes, and stroke. In conclusion, the present study demonstrates that stepwise, symptom-oriented therapy is feasible and effective in patients with coexisting HC and hypertension.

BACKGROUND: We have previously reported our 3-step repair for obstructive hypertrophic cardiomyopathy (HCM) consisting of resection of the septum, horizontal plication of the anterior mitral leaflet (AML), and release of abnormal papillary muscle attachments. This article reviews our complete experience with surgical management of HCM to better understand the role and relevance of mitral plication. METHODS: From 1997 to 2011, 132 patients with HCM underwent surgical treatment at our institution. Eighty-two patients (62%) received AML plication based on selection criteria and were classified as group A; patients in group B did not receive plication. All patients underwent preoperative and postoperative echocardiography. Long-term clinical follow-up was obtained by review of scheduled echocardiograms and direct patient interview. RESULTS: The average age of all patients was 55.5 years. Operative mortality was 0%. The mean left ventricular outflow tract (LVOT) gradient decreased from 118+/-41 mm Hg to 6+/-13 mm Hg (p<0.0001). Mean mitral regurgitation improved from 2.4+/-1.0 to 0.5+/-0.7 (p<0.0001). Postoperatively, 96.2% of patients had no residual systolic anterior motion (SAM). Significant improvements in heart failure classification and quality of life scores were noted for all patients. Comparison of groups A and B showed no statistically significant differences in outcomes, complications, or survival. Survival at 1, 5, and 10 years was 98%, 98%, and 92%, respectively. CONCLUSIONS: The heterogeneity of the pathologic process in HCM supports detailed analysis of the septum, mitral leaflets, and subvalvular apparatus. Surgical management of HCM that includes horizontal plication of a lax and elongated AML is safe and results in durable clinical and echocardiographic improvement.

AIMS: Echocardiographic contrast (EC) improves the diagnostic accuracy of suboptimal echocardiograms. In October 2007, the Food and Drug Administration (FDA) placed a black box warning on the label of the perflutren-based agents Definity and Optison, contraindicating their use in patients with pulmonary hypertension (PHT) and unstable cardiopulmonary status, after serious cardiopulmonary reactions occurred in temporal relation to EC administration. In 2008 and 2011, the FDA revised the black box warning allowing their use in this same population. However, limited data exist regarding the safety profile of these agents in patients with PHT. METHODS AND RESULTS: Consecutive hospitalized patients with PHT who were referred for echocardiographic evaluation, but required the use of EC, were included. All our patients received the EC agent Definity. We evaluated these patients for serious adverse events (respiratory decompensation, hypotension, syncope, convulsions, arrhythmias, anaphylactic reactions, or death) occurring within 24 h of EC administration. The study group included 1513 patients (age 69 +/- 14 years, 55% males, BMI 33 +/- 9 kg/m(2)), of which 911 (60%) had mild PHT, 515 (34%) had moderate PHT, and 87 (6%) had severe PHT. The mean pulmonary artery systolic pressures (PASP) in the groups with mild, moderate, and severe PHT were 41 +/- 4 (range 35-49) mmHg, 55 +/- 5 (range 50-69) mmHg, and 78 +/- 9 (range 70-122) mmHg, respectively. The incidence of adverse events in all subgroups was rare (0.002%) and they were not attributed to EC because of temporal and clinical considerations. CONCLUSION: The use of the EC agent Definity is safe in hospitalized patients with PHT.

Unique genetic characteristics of hypertrophic cardiomyopathy (HCM), including heterogeneity and incomplete penetrance, have made making predictions about prognosis complex. We reviewed data from septal myectomy results as published from 1980 to 2011, most of which come from specialized tertiary care centers. We also performed a retrospective review of 132 consecutive patients who underwent HCM surgery at our institution. At a mean follow-up of 4.2 +/- 3.2 years (range, 3 days to 14.2 years), there were no deaths within 30 days of surgery for our cohort. Over the course of 15 years, 2 deaths occurred in older patients, both of whom had surgery for HCM along with additional cardiac procedures. Age, the presence of comorbidities, and concomitant cardiac procedures were not statistically significant risk factors for mortality. Overall survival at 1, 5, and 10 years was excellent: 99%, 99%, and 92%, respectively. Surgical myectomy has been proven to be a safe and effective procedure for symptomatic obstructive HCM, and it confers excellent survival similar to that of the healthy population.

Sudden cardiac death (SCD) in young athletes is relatively uncommon but tragic when it occurs. Many of these deaths can be prevented by pre-exercise screening to identify cardiac abnormalities and those at high risk. Although recent research has provided much needed information on SCD in athletes, there remain significant gaps in the knowledge needed to determine an optimal screening protocol. This review examines the incidence and demographics of SCD in athletes and the difficulties in determining whether changes in an athlete's heart are due to training or represent a potentially malignant congenital abnormality. Current guidelines for screening and the intense debate over the use of the 12-lead electrocardiogram are discussed. Lastly, the importance of a response plan to an apparent SCD event that includes on-site/on-field automated external defibrillators will be discussed. A case study that illustrates the challenges in screening is presented.

Pharmacologic therapy is the first line approach to relieve symptoms in obstructive hypertrophic cardiomyopathy. There are no randomized trials to evaluate their effect on prognosis. Gradient reduction by surgical septal myectomy is associated with excellent prognosis, but not all patients have symptoms severe enough to require surgery; and, guidelines recommend operation only for patients with high gradients and symptoms unresponsive to pharmacologic therapy. The combination of disopyramide and beta-blockade is effective in reducing resting gradients (though not to the extent of surgery). This review examines the question of whether pharmacologic reduction of gradient in asymptomatic patients or those with milder symptoms might decrease HCM-related mortality.

Hypertrophic cardiomyopathy (HCM) occurs in 1 in 500 individuals. Treatment options for HCM differ from those administered in coronary disease, heart failure, and valvular disease patients that comprise the core of many cardiology practices. In this article, we offer a concise summary of the therapeutic use of disopyramide for reducing gradients and relieving symptoms in obstructive HCM.