Recurrent Hypotension During Hemodialysis Associated With Double Chamber Right Ventricle in Hypertrophic Cardiomyopathy

An 80-year-old man had recurrent hypotension and chest discomfort during hemodialysis. Blood pressure was 80/50 mmHg during dialysis and 130/80 mmHg after dialysis. Grade 4 systolic murmur was heard during dialysis, which decreased to grade 2 after dialysis.

On 2-D transthoracic echocardiography, interventricular septum (IVS) was asymmetrically hypertrophied without left ventricular outflow tract obstruction (Figure A). The right ventricle (RV) free wall was also hypertrophied and the RV cavity was separated into a double chamber RV (DCRV) by the hypertrophied RV wall and IVS (Figure B). Color Doppler indicated flow acceleration between the 2 chambers of the DCRV (Figure C) with a pressure gradient of 64.7 mmHg (Figure D). There was no other congenital heart disease. On cardiac catheterization with RV-gram, DCRV with elevated pressure in the proximal chamber (56 mmHg) and decreased pressure (13 mmHg) in the distal chamber was confirmed (Figure S1).

Figure.

Echocardiography. (A) Parasternal long axis view demonstrating asymmetrical septal hypertrophy (arrows: posterior wall thickness, 8 mm; arrowheads: interventricular septum thickness, 21 mm), typical characteristics of hypertrophic cardiomyopathy. (B,C) Parasternal short axis view at the aortic valve level showing (B) double chamber right ventricle (RV) and (C) flow acceleration (*) at the proximal RV (P-RV) outflow tract (P-RVOT) between the hypertrophied RV free wall and interventricular septum. (D) Continuous wave Doppler signal of the P-RVOT obtained in modified short axis view, showing a pressure gradient of 64.7 mmHg. D-RV, distal right ventricle; LV, left ventricle; PV, pulmonary valve.

We considered that the DCRV formed as a result of hypertrophic cardiomyopathy (HCM) of the RV, leading to dynamic RV outflow tract (RVOT) obstruction. During hemodialysis, reduced venous return aggravated RVOT obstruction and significantly reduced RV stroke volume, which resulted in decreased left side preload and, in turn, decreased cardiac output and hypotension. After initiation of β-blockers, increase of dialysis frequency and decrease of ultrafiltration, hypotension and chest discomfort were improved.

HCM involving RV and complicated with DCRV is very rare,¹ but can cause serious hemodynamic instability. Comprehensive evaluation on cardiac imaging is crucial for diagnosis and clinical decision-making.

Disclosures

The authors declare no conflict of interest.

Supplementary Files

Supplementary File 1

Figure S1. Cardiac catheterization.

Please find supplementary file(s);

http://dx.doi.org/10.1253/circj.CJ-17-1361

Reference

• 1.   Krecki R, Lipiec P, Piotrowska-Kownacka D, Chrzanowski L, Krolicki L, Drozdz J, et al. Predominant, severe right ventricular outflow tract obstruction in hypertrophic cardiomyopathy. Circulation 2007; 116: e551–e553.