Muddassir Mehmood

Comparison of right and left ventricular function and size in Duchenne muscular dystrophy

INTRODUCTION Right ventricular (RV) size and function in Duchenne muscular dystrophy (DMD) have not been well described. Using cardiac magnetic resonance (CMR) imaging we describe the relationship of RV and left ventricular (LV) size and function in a large DMD cohort. METHODS Latest CMR scans of 272 patients consecutively seen at a single tertiary referral center (2011-2014) with skeletal muscle biopsy confirmed DMD were included. 1.5 and 3 Tesla CMR scanners were used. Biventricular ejection fraction (EF), end-diastolic volume index (EDVI), mass and mass index were compared across categories of LVEF. RESULTS Mean age was 13.5 ± 4.9 years. 71% had normal (≥ 55%) LVEF while mild (EF 45-54%), moderate (EF 30-44%), and severe LV dysfunction (EF <30%) was present in 20%, 6% and 3% respectively. The correlation between RVEF and LVEF was weak. Even in patients with severe LV dysfunction, RVEF (49.7% ± 12.9%) was relatively preserved. There were no significant differences in RVEDVI and RV mass index across categories of LV function. CONCLUSION In a large DMD cohort, RVEF was relatively preserved and RV size was preserved across categories of LV dysfunction.

Hemodynamic response to treatment of iron deficiency anemia in pulmonary arterial hypertension: longitudinal insights from an implantable hemodynamic monitor

Despite new therapeutic options, pulmonary arterial hypertension (PAH) remains a progressive disease associated with substantial morbidity and mortality. As such, additional strategies for monitoring and adjunctive management of this disease are important. A 59-year-old woman with scleroderma-associated PAH received an implantable hemodynamic monitor (IHM) as part of a research protocol at our institution. Pulmonary artery pressures, heart rate, and cardiac output (sensor-based algorithm) were measured on a daily basis, and parameters of right ventricular (RV) performance and afterload were calculated. At the time of IHM implant, the patient had functional class III symptoms, was receiving triple-drug therapy, and had normal hemoglobin levels. Four months after implant, and with further optimization of prostacyclin therapy, she had improvement in her symptoms. However, shortly thereafter, while the patient was receiving stable drug therapy, her case regressed with worsening symptoms, and the patient received a new diagnosis of iron deficiency anemia. Oral iron supplementation resulted in normalization of hemoglobin levels and improvement in the patients iron profile. A gradual and sustained reduction in pulmonary pressures was noted after initiation of oral iron accompanied by increased RV performance and favorable reduction in RV afterload. The patient had significant symptomatic improvement. Iron deficiency is an underappreciated yet easily treatable risk factor in PAH. Use of IHM in this case longitudinally illustrates the optimization of pulmonary hemodynamics and RV afterload in tandem with clinical improvement achieved by a simple therapy.

Pulmonary Vascular Resistance: A Novel Method of Non-Invasive Estimation and Association with Mortality in Critically ill Surgical Patients

Doppler-derived ratio of peak tricuspid regurgitant velocity (TRV, ms) to the right ventricular outflow tract time velocity integral (TVIRVOT, cm) is a reliable non-invasive method of estimating pulmonary vascular resistance (PVR). The easier to measure left ventricular outflow tract time velocity

Cardiac Power Output in Critically Ill Surgical Patients: A Simultaneous Pulmonary Artery Catheterization and Transthoracic Echocardiography Study

Cardiac power output (CPO) (W) is a novel hemodynamic endpoint of resuscitation. A paucity of data exists as to the non-invasive estimation of CPO in surgical intensive care unit (ICU) patients. This 48 hours study enrolled 32 critically ill and/or injured adult surgical patients within 6 hours of