No abstract

A 74 year old woman had right to left shunting through an atrial septal defect despite normal right heart pressures. Acute volume expansion temporarily reduced the shunt. Contrast echocardiography and angiography demonstrated that this shunting occurred almost exclusively from the inferior vena cava. At surgery a redundant flap of septum secundum was found that was adjacent to the inferior vena cava orifice, intercepting its blood return like a spinnaker and shunting it into the left atrium.

Left ventricular filling pressure serves as a most useful haemodynamic index of cardiac dysfunction in acute myocardial infarction. In order to predict the filling pressure from the P wave of the electrocardiogram,flowdirected Swan-Ganz catheters were inserted in 40 acutely ill patients (36 with acute myocardial infarction or serious angina). An elementary electrocardiographic measurement, the P terminal force in lead Vi was found to be well and inversely correlated to the level of mean left ventricular filling pressure, particularly in patients with acute left heart failure (P< o ooI, r= -o82). Significant correlation (P< o ooI) was further noted between left ventricular filling pressure and clinical severity of acute myocardial infarction, mixed venous oxygen saturation, pulmonary radles, and radiological pulmonary vascular congestion. Absence of third andfourth heart sounds indicated normal left ventricularfilling pressure in acute myocardial infarction but the reverse was not found to be true. Acute sequential variations in left ventricular filling pressure were paralleled by the P terminal force more closely than any other recorded variable.It is concluded that P wave alterations provide a useful, simple, and noninvasive toolfor quantitative assessment of acute changes in LV preload in seriously ill patients.

SUMMARYThe circulatory and respiratory responses to five levels of treadmill exercise were recorded for 75 normal males divided equally in the age groups 20 to 29,30

The effects of a 7-month physical training program on the physiological responses to exercise and work capabilities of seven middle-aged, sedentary men have been evaluated. Testing involved bicycle ergometry and interval treadmill walking, as well as pre-and postconditioning hemodynamic investigations during five levels of treadmill walking up to a 25% grade.Significant alterations of several parameters were observed in the trained state. Resting and exercise bradycardia were marked, the lowest heart rate registered being 49/min. Maximal physical working capacities and maximal oxygen uptakes were uniformly increased with group means of + 22 and + 18%, respectively. Work load capacities at heart rates 130, 150, and 170 were also augmented.Resting and exercise cardiac output for a given oxygen uptake declined and produced relative hypokinesis. Stroke volume was greater at moderate and heaviest work loads. Cardiac minute work was reduced despite stroke volume increments.Pulse wave and arterial pressure analyses indicated that tension-time index and ejection-time index were markedly reduced, while maximal pressure derivative and ventricular ejection rate were increased.It is concluded that aside from subjective enhancement of well-being, a well-planned physical training program for middle-aged men can develop beneficial economy and efficiency of myocardial function and the oxygen transport system.