Cardiac resynchronization therapy: a possible option for refractory end-stage heart failure

Abstract

Background Cardiac resynchronization therapy (CRT) is an established option for patients with left ventricular (LV)asynchrony and heart failure (HF) in New York Heart Association (NYHA) Class III and stable patients in NYHA class IV. The application of CRT in an intensive care setting for patients with severe end stage refractory catecholamine dependent HF and LV asynchrony has not been highlighted so far. The case of a 64 year old female with dilated cardiomyopathy is reported. The patient was hospitalized for progressive dyspnea, hypotension, repetitive non sustained ventricular tachycardia, leg edema and renal failure under complete oral medication. Catecholamines had to be maintained at a minimum of 20 to 40 mg dobutamine/h. Treatment options included the implantation of abiventricular assist device or CRT. A stable catecholamine free status could not be achieved. Methods Dimensions of the heart, global ventricular function, heart valves and interventricular asynchrony were assessed by 2D and Doppler echocardiography.Intra LV asynchrony was assessed by tissue doppler. A CRT pacemaker and defibrillator (CRT-D) was implanted. Results The LV was dilated (71mm end diastolic) and the ejection fraction (EF) severely depressed (15%). Mitral regurgitation (MI) II° to III° was present. The interventricular mechanical delay (IVD) was 50 ms. The maximum intra LV difference (▵EMD max) of the electromechanical delay was 82 ms. The standard deviation of electromechanical delays (SDEMD) was 39ms. The myocardial performance index (MPI) was 1.75. After CRT-D implantation with mid lateral placement of the LV lead catecholamines could be discontinued within 20 hours, dyspnea and renal function improved rapidly. After 5 months LV diameter was 69mm, MI was I°. IVD was reduced to 10 ms, MPI to 0.63, EMDmax to 41 ms, SDEMD to 12 ms. The EF increased to 29% and the functional status was stable at NYHA class II to III. Conclusion Also in patients with catecholamine dependent refractory HF and marked LV asynchrony the implantation of a CRT device is a potentially helpful strategy which can avoid the application of an assist device and lead to stable improvement of hemodynamics and the patient's functional status. Further investigation is needed in this patient cohort.