Influence of heart rate on exercise-induced R-wave amplitude changes in coronary patients and normal subjects.

In order to study whether different heart rates achieved at peak exercise by normal subjects and patients with coronary artery disease (CAD) affect the results of analysis of R-wave amplitude changes (delta R), we evaluated delta R at progressively increasing heart rate (HR) steps in 60 normal subjects with negative exercise tests (ET), in 130 patients with CAD, in 88 patients with true positive and 42 with false negative ET, and in 43 patients with no CAD and false positive ET. We found that the sensitivity and specificity of delta R were HR dependent, the former decreasing and the latter increasing with progressively increasing HR steps. Mean values of delta R did not discriminate among the four groups for HRs up to 150 bpm; significant differences were found between normal subjects and CAD patients, both with true positive and false negative stress tests, at HR greater than 150 bpm.

Exercise induced ventricular arrhythmias. Angiographic correlation with the severity of coronary artery disease.

We correlated the incidence and degree of exercise induced ventricular arrhythmias (EIVA) with the angiographic severity of coronary artery disease (CAD) in 162 patients with a history of stable effort angina, all showing a positive exercise stress test for myocardial ischemia and a greater than or equal to 70% stenosis of a major coronary artery. Patients were grouped according to the following criteria: presence of electrocardiographic evidence of old transmural myocardial infarction (MI), number of significant coronary stenoses and number of left ventricular (LV) areas showing abnormal segmental wall motion (ASWM). The incidence of EIVA in patients with multivessel CAD was higher than in patients with single vessel CAD, but this difference was not statistically significant.

[Effectiveness of the aorto-coronary by-pass procedure in elderly patients].

This study was undertaken to evaluate the efficacy of coronary artery by-pass grafting (CABG) in elderly patients with coronary artery disease. A consecutive series of 79 patients, 65 years of age and older, who underwent CABG from 1975 to 1981 was analysed and their follow up status ascertained. This group was compared with a consecutive series of 397 patients under the age of 65 who underwent CABG during the same period.

Hemodynamics of the splanchnic and systemic circulation after hypotonic water load-comparison between normal subjects and patients with congestive heart failure.

The authors investigated the changes in cardiovascular and splanchnic hemodynamic, diuresis and urinary and hepatic veins osmolarity induced by hypotonic water load in five normal subjects and in five patients with congestive heart failure (CHF). Pulmonary wedge pressure increased significantly only in CHF patients while cardiac index, total pulmonary resistances and peripheral vascular resistances remained unchanged in both groups. Hepatic blood flow increased significantly in control group while in CHF showed a significant reduction 15 and 30 minutes after water load.

Effects of oral salt loading on beta-adrenergic receptor responsiveness in normal and hypertensive subjects.

The effect of oral salt loading (400 mmol per day of NaCl for 7 days) on cardiac and pancreatic beta-receptor responsiveness has been evaluated in 12 patients with established essential hypertension and in seven age-matched control subjects. Cardiac beta-receptor responsiveness was evaluated by assessing the dose of isoprenaline which increased a stable heart rate by 25% (chronotropic dose 25%, CD 25%). Pancreatic beta-receptor responsiveness was measured by the incremental areas of insulin secretion induced by iv infusion of increasing amounts of isoprenaline.

The autonomic nervous tone abnormalities in the genesis of the impaired baroreflex responsiveness in borderline hypertensive subjects.

1. The effects of intravenous administration of neostigmine and propranolol, individually or in combination, on baroreflex responsiveness have been evaluated in 18 borderline hypertensive subjects and in 14 age-matched control subjects. 2.

Inverted response of arginine vasopressin to postural change in patients with essential hypertension.

1. This study was designed to compare the response of plasma arginine vasopressin (AVP) to head-up tilt in hypertensive patients and in normals. 2.

Renal function in borderline hypertensive first-degree relatives of essential hypertensives. Effects of sodium load.

Renal function in the basal state and after sodium load has been investigated in 21 borderline, hypertensive, first-degree relatives of established hypertensives and in 21 age- and sex-matched, normal subjects with no family history of hypertension. During intravenous infusion of inulin and p-aminohippurate in saline, both groups showed a decrease in plasma aldosterone levels (p less than 0.05) but renal plasma flow (595 +/- 48 vs.

The reflex control of arginine-vasopressin release in essential hypertension.

1. The reflex control of arginine-vasopressin release was studied in 12 essential established hypertensive patients and in 12 age-matched normal subjects by comparing the effects of head-up tilt and a variable-pressure neck-chamber. 2.

Baroreflex responsiveness in borderline hypertensives: a study with neostigmine.

The baroreflex response to changes in transmural pressure throughout the arterial tree or limited to the carotid sinus was evaluated in ten borderline hypertensives and compared with that observed in ten normal subjects and in ten established hypertensives. Baroreceptor sensitivity was tested by evaluating both heart rate response to phenylephrine-induced increase in arterial pressure and heart rate and blood pressure changes induced by increased neck tissue pressure by means of a neck chamber. The heart rate response to phenylephrine (evaluated by the regression of the R-R interval versus the systolic blood pressure) was depressed both in borderline and established hypertensives as compared with controls.

Mechanisms underlying systemic hemodynamic responses to experimental coronary artery occlusion. A preliminary study with hexamethonium.

The hemodynamic changes induced by coronary occlusion were investigated in anesthetized dogs. Coronary occlusion elicited an immediate but transient increase in the systemic blood pressure and in the vascular resistance of the hind limb perfused at constant flow. Thereafter, systemic hypotension and vasodilatation in the perfused region were observed.

[Effects of guaiacolic ester of acetylsalicylic acid on spirometric and plethysmographic parameters in subjects with chronic obstructive bronchopneumopathy].

The effects of oral administration of guaiacolic ester of acetyl salicilic acid in 24 patients with chronic obstructive lung disease have been evaluated. 1.5 g of this drug were given daily into 3 administrations improving both objective and subjective symptomatology in 19 of the 24 patients after 1 or 3 weeks of treatment.

[The hemodynamic effects of reproterol in patients with chronic obstructive lung disease (author's transl)].

Our study was undertaken in order to evaluate hemodynamic effects of intravenous administration of Reproterol in patients with chronic obstructive lung disease (COLD). Reproterol is a monomulecolar combination of catecholamine and theophilline. Diastolic pulmonary pressure and wedge pressure decreased 20 minutes after Reproterol while total pulmonary resistances were reduced 10 minutes after drug administration; sistolic pulmonary pressure and cardiac index increased only after 10 minutes; heart rate increased until 15th minute.

[Influence of left ventricular volume changes induced by Valsalva maneuver on R wave amplitude (author's transl)].

Exercise-induced changes of R wave amplitude (delta R) during exercise has been employed to improve the reliability of stress testing in detecting patients with coronary artery disease. Several authors postulated that delta R are related to changes of ventricular volumes. Furthermore Valsalva Maneuver (VM) is able to induce a decrease of left ventricular volumes induced by VM and the variations of R wave.