B. Elias

A simplified echocardiographic technique for detecting continuous-flow left ventricular assist device malfunction due to pump thrombosis.

BACKGROUND Malfunction of a continuous-flow left ventricular assist device (CF-LVAD) due to device thrombosis is a potentially life-threatening event that currently presents a diagnostic challenge. We aimed to propose a practical echocardiographic assessment to diagnose LVAD malfunction secondary to pump thrombosis. METHODS Among 52 patients implanted with a CF-LVAD from a single center who underwent echocardiographic pump speed-change testing, 12 had suspected pump thrombosis as determined by clinical, laboratory, and/or device parameters. Comprehensive echocardiographic evaluation was performed at baseline pump speed and at each 1,000-rpm interval from the low setting of 8,000 rpm to the high setting of 11,000 rpm in 11 of these patients. RESULTS Receiver operating characteristic curves and stepwise logistic regression analyses showed that the best diagnostic parameters included changes in the LV end-diastolic diameter (<0.6 cm), aortic valve opening time (<80 msec), and deceleration time of mitral inflow (<70 msec) from lowest to highest pump speed. One parameter was predictive of pump malfunction, with 100% sensitivity and 89% specificity, whereas 2 of 3 parameters increased the sensitivity to 100% and specificity to 95%. CONCLUSIONS The 3 echocardiographic variables of measured changes in LV end-diastolic diameter, aortic valve opening time, and deceleration time of mitral inflow between the lowest (8,000 rpm) and highest pump speed settings (11,000 rpm) during echo-guided pump speed-change testing appear highly accurate in diagnosing device malfunction in the setting of pump thrombosis among patients supported with CF-LVAD. Further investigation is warranted to create and validate a prediction score.

A REVIEW OF INFECTIONS IN PATIENTS WITH LEFT VENTRICULAR ASSIST DEVICES: PREVENTION, DIAGNOSIS AND MANAGEMENT

Since the advent of ventricular assist devices with smaller configurations and continuous-flow technology, survival rates for patients with end-stage heart failure have dramatically improved. While the burden of infectious complications is decreased in patients on continuous-flow ventricular assist devices compared to bulkier pulsatile-flow devices, infection remains one of the most common causes of morbidity and mortality. The majority of infections occur at the driveline exit site, beginning with a disruption or trauma to the barrier between the skin and driveline and sometimes spreading deeper. Once infections develop, they can be difficult to eradicate. Depending on the degree of infection, treatment options may include local wound care, antibiotics, or surgical treatment. Preventive strategies and careful surveillance are crucial to improve patient outcomes.