Influence of aetiology on long-term effects of resynchronization on cardiac structure and function in patients treated with ß-blockers.

OBJECTIVES: Cardiac resynchronization therapy (CRT) elicits more beneficial effects on left-ventricular (LV) structure and function, and long-term clinical outcomes in nonischemic heart failure patients. Rates of ß-blocker use in recent heart failure trials are higher than in CRT trials and this may influence the response to CRT. This study examined the long-term effects of CRT on LV structure and function in New York Heart Association class III-IV ß-blocker-treated patients. METHODS: One hundred and four (41 ischemic and 63 nonischemic) CRT patients, who were receiving ß-blockers before and throughout 12 months following device implantation, were retrospectively selected. Variations in echocardiographic parameters recorded before, and 6 and 12 months after CRT were analyzed. RESULTS: Selected patients were all stable on ß-blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (97%) and diuretics (97%) before implantation. CRT was associated with significant improvements in LV morphological and systo-diastolic functional parameters at 6 months, with further improvements between 6 and 12 months seen in nonischemic patients only. Accordingly, rates of echocardiographic response to CRT were similar at 6 months but significantly higher in nonischemic patients after 1 year. The degree of reduction in LV diameters and volumes, and of increase in ejection fraction, was significantly larger in nonischemic patients at both 6 and 12 months. In addition, a significant reduction in LV mass and severity of mitral regurgitation was more evident in nonischemic patients both 6 and 12 months following CRT. CONCLUSIONS: Ischemic aetiology of heart failure is associated with less favorable long-term effects of CRT on LV structure and function despite the systematic use of ß-blockers.

Profiling cardiac resynchronization therapy patients: responders, non-responders and those who cannot respond--the good, the bad and the ugly?

Cardiac resynchronization therapy (CRT) is an effective option for the management of heart failure (HF) patients with left ventricular systolic dysfunction and prolongation of the QRS interval. Unfortunately, a variable proportion of eligible patients fail to benefit from this treatment, the so-called "non-responders". Despite intensive investigations aimed at identifying reliable diagnostic tools, additional to standard criteria, for the selection of responders, partly due to the complexity and multi-factorial nature of the mechanism underlying response, no conclusive evidence is currently available about which of the many variables assessed may predict individual response and should be included in selection criteria. Accordingly, even if labeled as a non-responder, a patient should receive a CRT device being the certain risk of withholding the treatment more consistent than the potential risk of being a non-responder. However, a possible third profile of patients along with responders and non-responders is emerging consisting of a limited subset of individuals, mainly among those with HF of ischemic aetiology, who simply do not possess the anatomical requisite for conventional biventricular pacing to be effective. Such patients may be referred to as those who cannot respond to CRT and their identification is potentially feasible by integrating non-invasive imaging findings and of clinical relevance in the definition of the therapeutic strategy. In conclusion, this review will provide an analysis of gathered data about the selection of candidates to CRT beyond responders and non-responders with the perspective of the potential characterization of patients who cannot respond to CRT.

Cardiogenic shock complicating myocardial infarction in a doped athlete.

Abuse of doping agents may pose a higher risk for heart disease including acute myocardial infarction. We report the case of a 50-year-old body-builder Caucasian man with a long-standing abuse of nandrolone and erythropoietin that developed a ventricular septal defect following acute myocardial infarction. This mechanical complication led to cardiogenic shock ultimately treated with the implantation of a circulatory support by means of extracorporeal membrane oxygenation. The patient subsequently underwent orthotopic heart transplantation. The association of intense isometric exercise, abuse of erythropoietin and nandrolone is likely to have predisposed to coronary thrombus formation and acute myocardial infarction, as the patient presented no traditional cardiovascular risk factors.

[An unusual cause of syncope in hypertrophic cardiomyopathy]. / Una rara causa di sincope nella cardiomiopatia ipertrofica.

Syncope and pre-syncope represent common symptoms in patients with hypertrophic cardiomyopathy. The clinical scenario of recurrent and frequent syncopal episodes is one of the most challenging in the management of patients with hypertrophic cardiomyopathy. Syncope in hypertrophic cardiomyopathy patients usually recognizes two underlying mechanisms: arrhythmias or primary hemodynamic mechanism. The concomitant presence of myocardial ischemia is one of the potential triggers in the context of syncope due to hemodynamic mechanism. Myocardial ischemia is not generally related to epicardial coronary artery atherosclerotic disease but rather to the presence of partially obliterated intramural coronary arteries or narrowed vessels. We report the rare case of a patient with hypertrophic cardiomyopathy presenting with recurrent syncopal episodes due to myocardial ischemia secondary to severe stenosis of the left anterior descending coronary artery.