Contractile pericarditis-like hemodynamics in dilated-phase hypertrophic cardiomyopathy with giant atrium

Abstract

A 47-year-old man with dilated-phase hypertrophic cardiomyopathy was admitted to the hospital with worsening heart failure. As the enlarged atrium caused a constrictive pericarditis-like hemodynamic condition, atrial wall resection and tricuspid valvuloplasty were performed. Postoperatively, pulmonary artery pressure rose due to increased preload; however, the rise in pulmonary artery wedge pressure was restrained, and the cardiac output significantly improved. When the pericardium is extremely stretched due to atrial enlargement, it can lead to an elevation of intrapericardial pressure, and both atrial volume reduction and tricuspid valve plasty could lead to increased compliance and contribute to hemodynamic improvement.

Learning objective: Atrial wall resection for massive atrial enlargement and tricuspid annuloplasty in patients with diastolic-phase hypertrophic cardiomyopathy effectively relieves unstable hemodynamics.

Keywords: Atrial wall resection; Contractile pericarditis; Dilated phase hypertrophic cardiomyopathy; Heart failure.

Fig. 1

Computed tomography (CT) images at pre- and post-surgery. (A) Cardiac CT, pre-surgery, showing a giant right atrium of 1292 ml and left atrium of 363 ml. (B) Cardiac CT, post-surgery, showing a right atrium of 354 ml and left atrium of 221 ml and dilation of the pulmonary artery (PA) diameter from 32.4 mm to 37.5 mm, after the enlarged right-left atrium was surgically sutured. LA, left, atrium; LV, left ventricular; RA, right atrium; RV, right ventricular.

Fig. 2

Simultaneous pressure waveforms of both ventricles pre- and post-surgery. (A) Simultaneous pressure of both ventricles showing equalization of right and left ventricular end-diastolic pressures like contractile pericarditis hemodynamics with a cardiac index of 2.3 L/min/m², two years before. (B) Post-surgery, this equalization of simultaneous pressure is released and despite a significant elevation of systolic right ventricular (RV) pressure, a minimal increase in left ventricular end-diastolic pressure is recorded due to decreased RV end-diastolic pressure with a cardiac index of 3.4 L/min/m². ECG, electrocardiogram; BW, body weight; HR, heart rate; ABP, arterial blood pressure; PAWP, pulmonary arterial wedge pressure; PAP, pulmonary arterial pressure; RVP, right ventricular pressure; RAP, right atrial pressure; LVP, left ventricular pressure; CO, cardiac output; CI, cardiac index; SVR, systemic vascular resistance; PVR, pulmonary vascular resistance; SVO₂, mixed venous oxygen saturation.

Fig. 3

Hemodynamic effects of morphological abnormalities. Hypertrophic cardiomyopathy with atrial fibrillation leads to an enlargement of the atrial volume. A left-right shunt formed by catheter ablation and tricuspid regurgitation due to severe tethering of the tricuspid valve leaflets accelerated atrial volume expansion, resulting in increased intracardiac pressure. Surgical intervention for atrial volume and tricuspid regurgitation can decrease intracardiac pressure and increase both ventricular compliance and preload, resulting in increased cardiac output.

Online Fig. 1

Histopathological myocardial tissue specimen from right atrium wall. Hematoxylin and eosin (H&E) staining of the myocardial tissue from the right atrial wall revealed extensive desquamation and sporadic degeneration.