Ventilation and haemodynamics in heart disease.

Exercise hyperpnea in chronic heart failure: relationships to lung stiffness and expiratory flow limitation

“…Pulmonary congestion and hypertension, edema, increased perivascular pressure, vascular thrombosis, increased heart size, and neurohumoral mechanisms may increase lung stiffness both at rest and during exercise (9,14,21,24,26,34,35). In addition, regional hypoperfusion may result in pneumoconstriction with local decrease in lung compliance (22).…”

“…The most prominent pulmonary abnormality in CHF is an increased lung stiffness (9,14,21,24,26,34,35). This may result from a number of mechanisms, including vascular congestion, interstitial edema and fibrosis, increased alveolar surface tension, ventilation inhomogeneities, and activation of contractile elements.…”

Failure of propranolol to improve exercise tolerance in patients with mitral stenosis in sinus rhythm.

“…4 Thus the increases in heart rate and cardiac output that occur during exercise lead to higher left atrial and pulmonary venous pressure, which are the presumed cause of the exertional dyspnoea of mitral stenosis.5 ,B blockade, by blunting the rises in heart rate and cardiac output during exercise, and thereby increasing the diastolic filling period and reducing transvalvar flow, would be expected to reduce the increase in pulmonary venous pressure at any given level of exercise. Indeed, in studies in which intravenous pronethalol' or propranolol2 3 were given to patients with mitral stenosis during diagnostic carRequests for reprints to Dr Mayer M Bassan, Jerusalem Heart Clinic, 12 Paran Street, Jerusalem, Israel.…”

Gas Exchange in Severe Chronic Obstructive Lung Disease in Relation to Inspired Oxygen and Increased Carbon Dioxide Fraction, Physical Exercise and Body Posture

“…During exercise some of the ventilatory variables remained higher in the sitting posture in the C-group (7 patients), but there was no consistent change in the R-group (3 patients). Two out of 7 C-group and all 3 R-group patients had elevated PCV pressures, which are known to increase ventilation in an increasing number of patients when they exceed about 25 mmHg (12). In some, but not all patients in this comparison, the increased PCV pressure might have increased the minute ventilation to a greater extent in the supine posture.…”