Invasive Assessment of Microvascular Resistance in Hypertrophic Cardiomyopathy With Echocardiographic Correlates.

INTRODUCTION: Hypertrophic cardiomyopathy (HCM) is often associated with ischaemia despite lack of focal epicardial coronary stenosis. Our aim was to assess invasive coronary microvascular circulation and correlate findings with echocardiography. METHODS: We prospectively enrolled patients with HCM and controls who were referred for diagnostic coronary angiography. A pressure-temperature sensor coronary guidewire was used with intracoronary injections of room-temperature saline to measure mean coronary transit time during rest and hyperaemia induced with intravenous adenosine. The index of microvascular resistance (IMR) was calculated. Left ventricular mass was calculated during echocardiographic studies. RESULTS: Patients with HCM (n=12) and controls (n=7), had similar demographics. Left ventricular ejection fraction was higher in HCM (76.7%±11.0% vs 55.0%±15.9%, p=0.003). IMR was non-significantly higher in HCM (21.7±10.2 vs 15.3±4.8, p=0.16). Only patients with HCM had abnormal IMR (>25). Coronary flow reserve was non-significantly higher in HCM (2.7±1.6 vs 2.1±1.2, p=0.34). IMR correlated with left ventricular mass in hypertrophic cardiomyopathy subjects (Pearson r=0.68, p=0.02). CONCLUSIONS: Microvascular dysfunction as assessed by IMR may be abnormal in HCM and is correlated with left ventricular mass.

Mediastinal monophasic synovial sarcoma with pericardial extension causing hemodynamic instability.

A 46-year-old man presented with mass on chest x-ray along with a 6-month history of weight loss, dyspnea and cough. He was hypotensive and an echocardiogram showed large extra-cardiac mass compressing the right ventricular outflow tract resulting in features of cardiac tamponade. Chest computed tomography revealed a mediastinal mass invading the pericardium adjacent to right ventricular outflow tract. Biopsy of the mass confirmed primary monophasic synovial sarcoma. Chemotherapy and radiotherapy along with anti-inflammatories were given as surgery was too high risk due to the location of the tumour and pericardial involvement. Patient responded briefly to the treatment with improvement in hemodynamic parameters but over next weeks he became less responsive to treatment with increasing size. He died 2 months after treatment commenced.