Long-lasting improvement after septal myectomy for hypertrophic obstructive cardiomyopathy

Hypertrophic Cardiomyopathy Is Predominantly a Disease of Left Ventricular Outflow Tract Obstruction

“…This observation holds major clinical implications for the management of HCM patients, given that subaortic obstruction is a major determinant of clinical outcome. 6,13,14,[31][32][33][34][35][36][37][38][39][40][41][42][43] In the present study, among those exercised HCM patients with no evidence of obstruction at rest, Ͼ50% generated gradients of at least 30 mm Hg immediately after exercise, a much higher proportion than that reported by Marwick et al 16 Nevertheless, the frequency and degree to which HCM patients can generate mechanical impedance to LV outflow during periods of exercise have been largely unresolved. Because exercise is the only provocative maneuver that is truly physiologically based and most relevant to conditions under which HCM patients incur symptoms, we selected upright exercise as the most appropriate and clinically applicable methodology to define the overall prevalence, clinical profile, and significance of outflow obstruction in a large, multicenter HCM cohort.…”

“…3,12-15,29 -41 Indeed, subaortic gradients in HCM may importantly affect clinical decision making in that severely symptomatic drug-refractory patients with outflow obstruction either at rest or only with physiological provocation are potential candidates for invasive septal reduction interventions (eg, surgical myectomy, or in selected cases alcohol septal ablation) to normalize LV pressures and to improve symptoms. 3,6,[33][34][35][36][37][38][39][40][41][42][43] Historically, HCM has been characterized as a predominantly nonobstructive disease, with most patients (ie, Ϸ70%) said to demonstrate the absence of an LV outflow tract gradient under basal conditions. 6,8,9,[12][13][14]18 Since the early hemodynamic studies of the 1960s, 2-5 a variety of pharmacological and other provocative maneuvers (eg, catecholamine-stimulating drugs such as dobutamine and isoproterenol, Valsalva maneuver, amyl nitrite inhalation, and premature ventricular contractions) have been used in both the cardiac catheterization and echocardiography laboratories to provoke latent outflow gradients in symptomatic HCM patients with little or no evidence of obstruction at rest.…”

“…2,3,15,16 Of note, we also identified important subgroups of patients without gradients at rest (or with Valsalva) who nevertheless developed hemodynamically significant LV outflow obstruction only with exercise, including some with severe gradients Ն50 mm Hg. Indeed, a substantial proportion of these patients had limiting heart failure symptoms; therefore, identification of latent, exercise-triggered obstruction not only defined the probable mechanism for such symptoms but in many cases also created important options for their relief with surgical or interventional septal reduction therapies [33][34][35][36][37][38][39][40][41][42][43] should conventional drug therapy fail. Certainly, without exercise echocardiography, the capability of such HCM patients to develop elevated LV intracavitary pressures during normal physical activity would have remained undefined.…”

Usefulness of real-time three-dimensional echocardiography for evaluation of myectomy in patients with hypertrophic cardiomyopathy

“…Currently, the primary options to achieve this aim include myectomy 4 -6 and septal alcohol ablation. [7][8][9][10][11] Realtime 3-dimensional echocardiography (RT3DE), recently developed and commercially available, provides a potential to visualize and quantify the structure of the LVOT in patients with HC and to simplify and refine the surgical plan for those undergoing myectomy. The purpose of this study was to initially apply RT3DE to show the anatomy of the LVOT and then intraoperatively evaluate the immediate effects of myectomy in patients with HC.…”

Surgery for Hypertrophic Obstructive Cardiomyopathy

“…Since the early 1960s, surgery (ie, ventricular septal myectomy) has been the primary treatment option for drug-refractory, severely symptomatic patients with the obstructive form of HCM. [5][6][7][8][9][10][11][12][13][14] See p 2033…”