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Examination of the influence of endogenously released NO on left ventricular (LV) relaxation in the isolated ejecting guinea pig heart under conditions of preload, afterload and heart rate reveals that endogenous NO released from coronary microvascular endothelial cells increases LV relaxation. Bradykinin and substance P, agonists for NO release, stimulate selective increase of LV relaxation without modulating the early systolic phase of contraction.

Exogenous nitric oxide exhibits myocardial relaxant effects in isolated ejecting heart without changing systolic function and is independent of vasodilator activity. The exogenous nitric oxide donor, sodium nitroprusside, induces concentration-dependent rise in coronary flow and faster early left ventricular (LV) pressure decrease. The guanosine 3,5-cyclic monophosphate-independent vasodilator nicardipine increases coronary flow but does not affect early LV pressure fall.

Cardiac power output is a direct measure of overall cardiac function that integrates both flow-and pressure-generating capacities of the heart. The present study assessed the reproducibility of cardiac power output and other more commonly reported cardiopulmonary exercise variables in patients with chronic heart failure. Metabolic, ventilatory and non-invasive (inert gas re-breathing) central haemodynamic measurements were undertaken at rest and near-maximal exercise of the modified Bruce protocol in 19 patients with stable chronic heart failure. The same procedure was repeated 7 days later to assess reproducibility. Cardiac power output was calculated as the product of cardiac output and mean arterial pressure. Resting central haemodynamic variables demonstrate low CV (coefficient of variation) (ranging from 3.4% for cardiac output and 5.6% for heart rate). The CV for resting metabolic and ventilatory measurements ranged from 8.2% for respiratory exchange ratio and 14.2% for absolute values of oxygen consumption. The CV of anaerobic threshold, peak oxygen consumption, carbon dioxide production and respiratory exchange ratio ranged from 3.8% (for anaerobic threshold) to 6.4% (for relative peak oxygen consumption), with minute ventilation having a CV of 11.1%. Near-maximal exercise cardiac power output and cardiac output had CVs of 4.1 and 2.2%, respectively. Cardiac power output demonstrates good reproducibility suggesting that there is no need for performing more than one cardiopulmonary exercise test. As a direct measure of cardiac function (dysfunction) and an excellent prognostic marker, it is strongly advised in the assessment of patients with chronic heart failure undergoing cardiopulmonary exercise testing. [ABSTRACT FROM AUTHOR]

The authors describe two cases of massive mitral annular calcification, initially picked up on echocardiography and suspected of being neoplastic. Subsequent evaluation by CT scanning confirmed the location, aetiology, structure and diagnosis. Both cases demonstrated large masses, with calcification of varying density. This is likely explained by the presence of the previously reported amorphous caseous material demonstrated to be present within such mass structures. Such a feature is described as caseous degeneration. Both patients described have been managed conservatively with medical therapy, predominantly due to their age and general frailty. [ABSTRACT FROM AUTHOR]

Abstract: A 33-year-old man presented with an acute myocardial infarction (MI) after a recent long-haul flight. Angiography revealed thrombus in the right and circumflex coronary artery but no underlying atherosclerosis. Echocardiography revealed the presence of an atrial septal defect (ASD). In view of the recent flight, the presence of an ASD and occlusive thrombi in two coronary arteries, it was considered that the pathophysiological cause was paradoxical embolisation. Transcutaneous device closure of the ASD was implemented to prevent further catastrophic paradoxical embolic events. [Copyright &y& Elsevier]

The article presents a case study on the size, friability, location and histological type of primary cardiac tumours. Cardiac angiosarcomas are frequently first noticed by two-dimensional echocardiography and approximately 80% are located in the right atrium. Histologically, cardiac angiosarcomas usually show evidence of endothelial differentiation, having vascular channels formation. INSET: Case Report.

Myotonic dystrophy (MD) is an autosomal dominant disorder which affects both smooth and skeletal muscles. The incidence is approximately 1 in 8,000 births. It is the most common muscular dystrophy to manifest in adulthood, and the second most common skeletal muscle disorder after Duchenne MD. Cardiac rhythm disturbances are a common cause of death in these patients. This lesson describes a case in which a previously undiagnosed case of MD presented with an episode of ventricular fibrillation. [ABSTRACT FROM AUTHOR]