Non-pharmaceutical Interventions for Hypertrophic Cardiomyopathy: A Mini Review

Hypertrophic cardiomyopathy is an inherited cardiovascular disease, and 70% of patients have left ventricular outflow tract obstruction. Ventricular septal myectomy has been the gold standard treatment for most patients with refractory symptoms. Due to higher mortality associated with medical facilities with less experience, alcohol septal ablation has been accepted as an alternative to conventional surgical myectomy. It offers lower all-cause in-hospital complications and mortality, which could be potentially more preferable for patients with serious comorbidities. In recent years, radiofrequency ablation, providing another option with reproducibility and a low risk of permanent atrioventricular block, has become an effective invasive treatment to relieve left ventricular outflow tract obstruction. Moreover, substantial progress has been made in gene therapy for hypertrophic cardiomyopathy. The principal objective of this review is to present recent advances in non-pharmaceutical interventions in hypertrophic cardiomyopathy.

Pseudo-Paradoxical Jet Flow in a Patient with Midventricular Obstructive Hypertrophic Cardiomyopathy

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Additional apical obstruction may lower LV obstruction flow velocity.

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LV systole may last to the end of IVRT.

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PSS may cause intraventricular flow.

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Isovolumic relaxation flow does not always imply the presence of apical aneurysm.

Mitral Hemi-Arcade: A Rare Variant of a Rare Disease

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A case of a healthy young male with chest pain and borderline electrocardiogram is presented.

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Imaging showed a mitral hemi-arcade with left ventricular outflow tract obstruction during exercise.

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Previously postulated mechanisms for this obstruction are reviewed in this article.

Hypertrophic obstructive cardiomyopathy

Hypertrophic obstructive cardiomyopathy is an inherited myocardial disease defined by cardiac hypertrophy (wall thickness ≥15 mm) that is not explained by abnormal loading conditions, and left ventricular obstruction greater than or equal to 30 mm Hg. Typical symptoms include dyspnoea, chest pain, palpitations, and syncope. The diagnosis is usually suspected on clinical examination and confirmed by imaging. Some patients are at increased risk of sudden cardiac death, heart failure, and atrial fibrillation. Patients with an increased risk of sudden cardiac death undergo cardioverter-defibrillator implantation; in patients with severe symptoms related to ventricular obstruction, septal reduction therapy (myectomy or alcohol septal ablation) is recommended. Life-long anticoagulation is indicated after the first episode of atrial fibrillation.

Biphasic Force-Frequency Relation Predicts Primary Cardiac Events in Patients With Hypertrophic Cardiomyopathy

BACKGROUND

The force-frequency relation (FFR) is a hemodynamic index of the chronotropic relationship between left ventricular (LV) systolic function (percent change in dP/dt_max) and elevation of heart rate. FFR is a marker of myocardial contractile reserve and follows an upward slope in healthy myocardium [monophasic FFR (MoF)], a pattern that becomes biphasic (BiF) under pathological conditions. However, it remains uncertain whether the FFR determines a patient's prognosis. We investigated the promising role of the FFR as a predictor of cardiac events in the setting of hypertrophic cardiomyopathy (HCM).Methods and Results:A total of 113 consecutive patients with HCM (New York Heart Association (NYHA) class I-II) were retrospectively evaluated; 27 (23.9%) had a BiF pattern and they experienced a higher incidence of cardiac events compared with those showing an MoF pattern (median follow-up, 4.7 years; P<0.001). Furthermore, Cox proportional hazard regression analysis revealed that the LV end-diastolic volume index (hazard ratio: 1.051, P=0.014) and BiF pattern (hazard ratio: 15.260, P=0.001) were independent predictors of primary cardiac events. Interestingly, abnormal reductions in myocardial regulatory molecules related to contractility (SERCA2α) were observed exclusively in the patients exhibiting a BiF pattern.

CONCLUSIONS

The FFR reflects latent myocardial abnormalities and predicts cardiac events in the setting of HCM, even during the asymptomatic stages of the disease.