# Hypertrophic Obstructive Cardiomyopathy During Pregnancy: A Report of Two Cases

## TL;DR

This paper reports on two cases of pregnant women with hypertrophic obstructive cardiomyopathy, highlighting the risks and management strategies during pregnancy.

## Contribution

The study provides clinical insights into managing hypertrophic obstructive cardiomyopathy during pregnancy through a two-patient case series.

## Key findings

- Pregnancy in patients with hypertrophic obstructive cardiomyopathy requires close hemodynamic monitoring.
- Dynamic left ventricular outflow tract obstruction can worsen during pregnancy due to physiological changes.
- Individualized counseling and multidisciplinary care are essential for managing high-risk pregnancies in these patients.

## Abstract

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy caused by pathogenic variants in sarcomeric proteins and defined by left ventricular (LV) wall thickness ≥15 mm at end diastole in the absence of abnormal loading conditions. Hypertrophic obstructive cardiomyopathy (HOCM) is the obstructive phenotype of HCM characterized by dynamic left ventricular outflow tract (LVOT) obstruction, most often driven by septal hypertrophy and systolic anterior motion (SAM) of the mitral valve, frequently with mitral regurgitation. Pregnancy is generally well-tolerated in women with HCM; however, outcomes may be worse when significant left ventricular outflow tract obstruction (LVOTO) is present. Pregnancy-related increases in heart rate and reductions in systemic vascular resistance may intensify dynamic LVOTO, particularly when preload or afterload decreases. In severe symptomatic cases, pregnancy may be contraindicated (modified World Health Organization (mWHO) class IV, an extremely high-risk category in which pregnancy is generally discouraged) and therefore requires individualized counseling and specialized multidisciplinary care. This report describes two cases (a two-patient case series) of pregnant women with HOCM who required close hemodynamic monitoring and optimized peripartum management.