Cardiac Catheterization in a Patient with Obstructive Hypertrophic Cardiomyopathy and Syncope

Keywords
Cardiomyopathy, Hypertrrophic; Cardiac Catheterization; Syncope

A 35-year-old man sought medical care for recurrent syncope episodes related to moderate exertion in the past 2 months. Upon physical examination, the presence of a rude systolic murmur on the left sternal border was identified. The echocardiogram disclosed a moderate increase in the left atrium and significant hypertrophy of the interventricular septum with an estimated maximum diastolic diameter of 31 mmHg and a maximum left ventricular outflow tract gradient of 56 mmHg. The 24-hour Holter assessment showed the presence of frequent ventricular extrasystoles and an episode of nonsustained ventricular tachycardia. He was prescribed metoprolol 50 mg daily and, based on the high risk of sudden death, received an implantable cardioverter-defibrillator.

Despite the progressive increase in beta-blocker doses, the patient remained quite symptomatic with daily episodes of lipothymia and angina pectoris at minor exertion. Invasive strategy to reduce the intraventricular gradient was planned and the patient underwent a hemodynamic study to better assess the coronary and interventricular septum anatomy. The coronary angiography showed extrinsic compression of the first diagonal branch and septal arteries (Panel A). Simultaneous ventriculography of both ventricles disclosed significant hypertrophy of the medial and basal portions of the interventricular septum (Panel B) with left ventricular outflow tract obstruction (Panel C). The isoproterenol infusion during manometry resulted in increased intraventricular gradient from 30 mmHg to 130 mmHg, which revealed an important dynamic obstructive component. The patient was submitted to septal myectomy with no complications, with a significant reduction in the intraventricular gradient.

Figura 1
(A) Compressão extrínseca do ramo diagonal e ramos septais (seta branca). (B) Ventriculografia dos ventrículos direito e esquerdo, mostrando hipertrofia importante do septo interventricular durante a diástole e (C) obstrução da via de saída do ventrículo esquerdo durante a sístole final.

• Sources of Funding
  There were no external funding sources for this study.

• Study Association
  This study is not associated with any thesis or dissertation work.

Publication Dates

• Publication in this collection
  Sept 2017

History

• Received
  03 Jan 2017
• Reviewed
  24 Jan 2017
• Accepted
  24 Jan 2017