Prognostic value of left ventricular hypertrophy and geometry in patients with a first, uncomplicated myocardial infarction

BACKGROUND

The prognostic impact of left ventricular (LV) geometry on cardiovascular risk for patients with a first, uncomplicated acute myocardial infarction (AMI), and echocardiographic ejection fraction > or =50% has not been well described.

METHODS AND RESULTS

Accordingly, 111 AMI consecutive patients (mean age 59.3+/-10 years) performed echocardiographic examination at predischarge. LV mass was calculated by means of Devereux's formula and subsequently indexed by body surface area. Fifty-three patients had LV hypertrophy and 58 patients had normal LV mass. The two groups were homogeneous for demographic, clinical and angiographic variables as well as for the incidence of residual ischemia on predischarge stress testing. During follow-up period there were 24 cardiac events (cardiac death, unstable angina and non-fatal reinfarction) in the 53 patients with LV hypertrophy and only four events in the remaining 58 patients without LV hypertrophy (RR=2.45; CI=1.76-3.41; P<0.0001). The patients with concentric LV hypertrophy showed a higher incidence of events (64%) than patients with eccentric LV hypertrophy (32%, P<0. 05) and patients with normal geometry and mass (6%, P<0.0001). Multivariate Cox regression model identified concentric geometry as the most powerful predictor of combined end-points (chi(2)=32.7, P<0. 0001).

CONCLUSIONS

An increased LV mass and concentric geometry resulted important independent markers of an adverse outcome in patients with a first, uncomplicated myocardial infarction and good LV function.

[Multiple rhabdomyomas in a newborn infant. A clinical case report]

Rhabdomyoma is a rare primary benign cardiac tumor usually diagnosed in newborn and infancy. The authors report a case of multiple and completely asymptomatic rhabdomyoma, diagnosed by echocardiography.

Usefulness of the severity and extent of wall motion abnormalities as prognostic markers of an adverse outcome after a first myocardial infarction treated with thrombolytic therapy

The prognostic value of wall motion score index (WMSI), assessed at predischarge after a first acute myocardial infarction (AMI) in the thrombolytic era, is still not well known. One-hundred forty-four consecutive patients with a first AMI treated with thrombolytic therapy underwent exercise testing and echocardiography at rest before discharge and were followed-up for a mean period of 18 months. During follow-up, there were 32 cardiac events (12 patients had cardiac deaths, 8 had unstable angina pectoris, 1 had nonfatal reinfarction, and 11 patients had congestive heart failure). The patients who experienced any cardiac event had a higher WMSI (1.67+/-0.15 vs. 1.30+/-0.16, p<0.0001), a higher end-systolic volume (75.1+/-34 vs. 59.5+/-22 ml, p<0.01), and a lower ejection fraction (47+/-16% vs. 55+/-10%, p<0.001) at predischarge than patients without events. The incidence of a positive predischarge exercise testing did not differ between patients with and without cardiac events (22% vs. 24%, p = NS). Multivariate Cox regression analysis, including clinical, exercise results, and echocardiographic parameters, showed that the most powerful predictor of a subsequent event was a resting WMSI > or =1.50 before discharge (chi-square 17.8, p<0.0001). Thus, in patients with a first AMI who underwent thrombolysis, the severity and extent of echocardiographically detected wall motion abnormalities are important independent predictors of cardiac events.

Low-dose dipyridamole infusion acutely increases exercise capacity in angina pectoris: a double-blind, placebo controlled crossover stress echocardiographic study

OBJECTIVES

The aim of this study was to assess whether endogenous accumulation of adenosine, induced by low-dose dipyridamole infusion, protects from exercise-induced ischemia.

BACKGROUND

Adenosine is a recognized mediator of ischemic preconditioning in experimental settings.

METHODS

Ten patients (all men: mean age 63.4 +/- 7.3 years) with chronic stable angina, angiographically assessed coronary artery disease (n = 7) or previous myocardial infarction (n = 3) and exercise-induced ischemia underwent on different days two exercise-stress echo tests after premedication with placebo or dipyridamole (15 mg in 30 min, stopped 5 min before testing) in a double-blind, placebo controlled, randomized crossover design.

RESULTS

In comparison with placebo, dipyridamole less frequently induced chest pain (20% vs. 100%, p = 0.001) and >0.1 mV ST segment depression (50% vs. 100%, p < 0.05). Wall motion abnormalities during exercise-stress test were less frequent (placebo = 100% vs. dipyridamole = 70%, p = ns) and significantly less severe (wall motion score index at peak stress: placebo = 1.55 +/- 0.17 vs. dipyridamole = 1.27 +/- 0.2, p < 0.01) following dipyridamole, which also determined an increase in exercise time up to echocardiographic positivity (placebo = 385.9 +/- 51.4 vs. dipyridamole = 594.4 +/- 156.9 s, p < 0.01).

CONCLUSIONS

Low-dose dipyridamole infusion increases exercise tolerance in chronic stable angina, possibly by endogenous adenosine accumulation acting on high affinity A1 myocardial receptors involved in preconditioning or positively modulating coronary flow through collaterals.

C-reactive protein as a marker for cardiac ischemic events in the year after a first, uncomplicated myocardial infarction

The prognostic role of C-reactive protein levels in patients with a first acute myocardial infarction, an uncomplicated in-hospital course, and the absence of residual ischemia on a predischarge ergometer test and with an echocardiographic ejection fraction > or = 50% has not been described. C-reactive protein was determined during hospitalization in 64 patients (55 men, mean age 64.6 +/- 10.4 years). The patients were followed up for 13 +/- 4 months and the following cardiac events were recorded: cardiac death, new-onset angina pectoris, and recurrent myocardial infarction. Patients who developed cardiac events during the follow-up period had significantly higher C-reactive protein values than patients without events (3.61 +/- 2.83 vs 1.48 +/- 2.07 mg/dl, p <0.001). The probability of cumulative end points was: 6%, 12%, 31%, and 56% (p = 0.006; RR 3.55; confidence interval 1.56 to 8.04), respectively, in patients stratified by quartiles of C-reactive protein (< 0.45, 0.45 to 0.93, 0.93 to 2.55 and > 2.55 mg/dl). In the Cox regression model, only increased C-reactive protein levels were independently related to the incidence of subsequent cardiac events (chi-square 9.8, p = 0.001). Thus, increased C-reactive protein levels are associated with a worse outcome among patients with a first acute myocardial infarction, an uncomplicated in-hospital course without residual ischemia on the ergometer test, and with normal left ventricular function.

Left origin of the atrial esophageal signal as recorded in the pacing site

Clear atrial depolarizations from inside the esophagus have always been recorded in electrocardiology, but their precise origin is still under discussion. Though atrial signals are recorded along most of the esophagus, pacing of the atria is possible only in a short tract, probably where the esophagus is in contact with the posterior left atrium wall. In order to ascertain which portion of atria gives rise to the esophageal atrial signal recorded in the atrial pacing segment, we examined 37 patients with normal P waves on the standard ECG by inserting esophageal and endocavitary catheters. The interval between the earliest start of the P wave and the bipolar atrial deflection, was measured both through the esophagus (PA-Eso) and the Hisian region (PA-His) (the latest depolarization of interatrial septum). The former was longer than the latter (P < 0.001) in 36 of 37 patients, showing that the esophagus recorded atrial signal, at the site of effective pacing, originates outside the interatrial septum. As the atrial depolarization recorded through the esophagus is significantly delayed compared with the Hisian region recording, a pure left origin of the esophageal signal can be hypothesized. This is supported by the well-known delayed depolarization, during sinus rhythm, of the left atrium posterior wall compared with the right atrium and interatrial septum. Measuring the interval between the standard ECG P wave and atrial depolarization recorded through esophagus in the site of effective pacing, provides a reliable noninvasive estimate of interatrial time conduction.

Combined therapy with benazepril and amlodipine in the treatment of hypertension inadequately controlled by an ACE inhibitor alone

In a multicenter, randomized, double-blind, placebo-controlled study, we evaluated the efficacy and tolerability of the combination of benazepril, 10 mg, and amlodipine, 2.5 or 5 mg once daily, compared with benazepril, 10 mg, monotherapy in patients with hypertension inadequately controlled with angiotensin-converting enzyme (ACE)-inhibitor monotherapy. After a 2-week placebo and 4-week single-blind benazepril, 10 mg once daily, run-in period, 448 patients, 213 men and 235 women, aged 24-73 years (mean, 55 years), with mean diastolic blood pressure (DBP) > or =95 and < or =120 mm Hg at the end of the benazepril run-in period, were randomized to receive one of the following treatments once daily for 8 weeks: (a) benazepril, 10 mg, plus placebo (BZ10); (b) benazepril, 10 mg, plus amlodipine, 2.5 mg (BZ10/AML2.5); or (c) benazepril, 10 mg, plus amlodipine, 5 mg (BZ10/AML5). Before the patients were admitted to the trial, at the end of the placebo run-in and the benazepril run-in period and at the end of weeks 4 and 8 of the treatment period, sitting and standing blood pressure (BP), heart rate (HR), and body weight were measured 22-26 h after the intake of the trial medication. Both BZ10/AML2.5 and BZ10/AML5 combinations showed better antihypertensive activity than did BZ10 monotherapy at the terminal visit as demonstrated by (a) the 24-h postdosing sitting and standing systolic BP (SBP) and DBP values, which were statistically lower with combination therapy than with BZ10; (b) the success rate, which was statistically higher with both the combinations (69.2% in the BZ10/AML2.5 and 65.8% in the BZ10/AML5 group) compared with the BZ10 group (40.5%). The tolerability was good in the three treatment groups. No significant abnormal laboratory data were detected. There was no difference in efficacy and safety/tolerability between the BZ10/AML2.5 and BZ10/AML5 groups.

Valsartan, a new angiotensin II antagonist for the treatment of essential hypertension: a comparative study of the efficacy and safety against amlodipine

OBJECTIVE

To compare the antihypertensive efficacy of a new angiotensin II antagonist, valsartan, with a reference therapy, amlodipine.

METHODS

One hundred sixty-eight adult outpatients with mild to moderate hypertension were randomly allocated in double-blind fashion and equal number to receive 80 mg valsartan or 5 mg amlodipine for 12 weeks. After 8 weeks of therapy, in patients whose blood pressure remained uncontrolled, 5 mg amlodipine was added to the initial therapy. Patients were assessed at 4, 8, and 12 weeks. The primary efficacy variable was change from baseline in mean sitting diastolic blood pressure at 8 weeks. Secondary variables included change in sitting systolic blood pressure and responder rates.

RESULTS

Both valsartan and amlodipine were effective at lowering blood pressure at 4, 8, and 12 weeks. Similar decreases were observed in both groups, with no statistically significant differences between the groups for any variable analyzed. For the primary variable the difference was 0.5 mm Hg in favor of valsartan (p = 0.68; 95% confidence interval, -2.7 to 1.7). Responder rates at 8 weeks were 66.7% for valsartan and 60.2% for amlodipine (p = 0.39). Both treatments were well tolerated. The incidence of drug-related dependent edema was somewhat higher in the amlodipine group, particularly at a dose of 10 mg per day (2.4% for 80 mg valsartan; 3.6% for 5 mg amlodipine; 0% for valsartan plus 5 mg amlodipine; 14.3% for 10 mg amlodipine).

CONCLUSIONS

The data show that valsartan is at least as effective as amlodipine in the treatment of mild to moderate hypertension. The results also show valsartan to be well tolerated and suggest that it is not associated with side effects characteristic of this comparator class, dihydropyridine calcium antagonists.

Twenty-four-hour antihypertensive efficacy of felodipine 10 mg extended-release: the Italian inter-university study

We assessed the 24-h antihypertensive efficacy of an extended-release (ER) 10-mg formulation of the dihydropyridine felodipine in mild-to-moderate essential hypertension [World Health Organization (WHO) stage I-II]. Thirty patients, 23 men and 7 women, aged 37-70 years (mean 53 +/- 9 years) participated in a double-blind, randomized, cross-over study of felodipine 10 mg ER versus placebo. An ambulatory daytime diastolic blood pressure (DBP) >90 mm Hg at the end of a 4-week run-in period was necessary to enter the 10-week treatment phase. Twenty-nine patients completed the treatment phase. Twenty-two underwent a 2-day single-blind placebo follow-up to assess residual drug effects. All patients underwent ambulatory BP monitoring (ABPM) by Spacelabs 90207 recorders. Recorders were programmed to make automatic BP and heart rate (HR) measurements every 15 min throughout the 24 h. Felodipine 10 mg ER significantly (p < 0.01) reduced ambulatory systolic BP (SBP) and DBP values throughout the 24-h, day (7 a.m. to 11 p.m.) and night (11 p.m. to 7 a.m.) periods, but not influencing average ambulatory HR values. Trough-to-peak (T/P) ratios, calculated on the average ambulatory BP values measured in the 7-9 a.m. 2-h interval of the second day of ABPM (before the new drug administration: trough) and in the 10 a.m. to 12 noon 2-h interval of the first day of ABPM (peak BP-lowering effect), were 0.71 and 0.58 for SBP and DBP, respectively. Individual T/P calculations, after post hoc selection of nonresponders, gave superimposable results, the consistency of which was judged on mean, median, and confidence intervals (CI). However, the wide variability of the individual T/P ratios suggests that this method cannot be the only means to evaluate the duration of action of an antihypertensive drug by ABPM. The long-acting BP-lowering drug effect was clearly shown by the ABPM performed in the follow-up when SBP and DBP average values of the 24-h, day, and night periods were still reduced. Felodipine 10 mg ER effectively reduced BP in patients with mild-to-moderate hypertension, showing prolonged duration of its antihypertensive action beyond the time of the next dose.

Leucocytes and free radicals in stable angina pectoris

Bicycle ergometer exercise was used to induce ischemia in 20 patients with stable angina pectoris (SAP). Superoxide dismutase (SOD) blood concentrations, free radical generation (by the SOD-inhibitable reaction of ferricytochrome C), malondialdehyde (MDA) plasma concentrations, the unfractionated leucocyte filterability rate and the filterability rates of the granulocyte and mononuclear sub-fractions (using a positive pressure filtration system and 5 mu diameter Nuclepore filters), were monitored before and after exercise in the patients and in 18 matched controls. At the onset of ischemia a significant increase in the level of MDA plasma concentrations and significant decreases in both SOD blood concentrations and the SOD-inhibitable reduction of ferricytochrome C indicated oxygen free radicals had been released in the SAP patients. These changes were associated with significant impairments of granulocyte and unfractionated leucocyte filterabilities and with morphological evidence of granulocyte activation.

[The Study Group of Quinapril in Arterial Hypertension. The Steering Committee]

The efficacy and safety of the treatment of arterial hypertension with the ACE-inhibitor quinapril, were evaluated in a multicentre study conducted in Italy. The study, lasting 14 weeks, after a preliminary wash-out period, allowed response-based titration of quinapril dose from 10 mg to 40 mg once a day, with provision to combine additional hydrochlorothiazide (12.5 to 25 mg), in case of persistently high diastolic pressure levels. The efficacy sample included 1267 patients: at therapy week 14, 78.6% of patients were treated with quinapril alone. Global response rate (intent-to-treat) was 83.3%, with a mean reduction of diastolic pressure of 15.8 mmHg (95% confidence interval from 15.5 to 16.2 mmHg). 91 patients reported 126 associated adverse events (7.0%); the most frequently reported event was cough (2.7%). First-dose hypotension was rarely reported (1.3%), even in elderly and diabetic patients.

[Recent findings on the physiopathology of hypertension]

The numerous pathophysiological theories in the field of essential hypertension are often conflicting, and till now a comprehensive model is not available. The aetiology of human hypertension is probably multifactorial, the control mechanisms of hypertension are strictly interdependent, and the alteration of one induces readjustment of the others, so that it is very difficult to discriminate the "primum movens" from its consequences. In this review the recent acquisitions in the aetiology and the pathophysiology of arterial hypertension are analysed, with particular regard to the role of inheritance, of renal mechanisms of sodium retention, ions transport, humoral factors, central nervous system and of enhanced vascular reactivity. The activation of some of these pathophysiological factors induces the rise in peripheral vascular resistance, which is the final common pathway in the development of essential hypertension.

[Abnormal origin of the left coronary artery from the pulmonary artery. Description of a rare case in adulthood]

The anomalous origin of the left coronary artery from the pulmonary artery is a rare and usually fatal congenital malformation. The Authors present a case of anomalous left coronary artery arising from the pulmonary artery diagnosed in an adult patient.

Verapamil 240 SR versus verapamil 120 SR in arterial hypertension. A randomized double-blind, placebo-controlled study with 24-hour ambulatory blood pressure monitoring

Fifteen patients (6 males, 9 females), age range 36-70 years, were enrolled in a randomized, double-blind, placebo-controlled study according to a Latin-square design, with the aim of comparing 24-hour blood pressure profiles after three 15-day treatment periods with placebo, verapamil SR 120 mg (V120 SR) given twice daily (bid), and verapamil SR 240 mg (V240 SR) given once daily (od). All of the patients were diagnosed as mild or moderate essential hypertensives on the basis of standard casual recordings. Noninvasive 24-hour ambulatory blood pressure (BP) monitoring was performed with an ICR Spacelab 5200 automatic device. In comparison with placebo, a clinically and statistically significant reduction in both systolic and diastolic BP over 24 hours was obtained with both active treatments. Comparison of the two active treatments shows that V240 SR led to a greater reduction in systolic and diastolic BP than V120 SR. No changes in heart rate were observed. Both treatments were well tolerated. In conclusion, both verapamil regimens proved to be effective and safe in treating essential hypertensives, with V240 SR giving better 24-hour BP control.

[Simvastatin versus gemfibrozil in the treatment of primary hypercholesterolemia in hypertensive patients treated with hydrochlorothiazide]

Recent pharmacological studies confirmed the role of hypercholesterolemia in the pathogenesis of coronary atherosclerosis. A 10% reduction in cholesterol levels can reduce the risk of coronary heart disease by 15%. However many hypercholesterolemic patients often suffer from arterial hypertension and drugs such as thiazide diuretics cause an imbalance in lipid metabolism. The efficacy and the tolerability of simvastatin (a inhibitor of HGM-CoA reductase) with that of gemfibrozil (a fibric acid derivative, which can reduce the VLDL level) were compared in a placebo-controlled study in 2 groups of patients with primary hypercholesterolemia and mild-to-moderate essential hypertension treated with hydrochlorothiazide. After 10 weeks standard hypolipidemic diet and hydrochlorothiazide (25 mg od) therapy, 30 patients whose cholesterol levels were still greater than or equal to 250 mg/100 ml and whose diastolic blood pressure was less than 95 mmHg were randomized to one of the following treatments: simvastatin, 20 mg od, gemfibrozil, 600 mg bid or placebo, while continuing dietetic and diuretic treatment. After 24 weeks treatment, simvastatin induced a 37% reduction in cholesterol plasma levels, a 9% increase of HDL and a 16% reduction of LDL. APO-A1 showed a 4% increase, while APO-B showed a 3% reduction. Gemfibrozil induced a 20% reduction in plasma triglycerides and a 13% decrease in plasma cholesterol, with a significant 19% increase in HDL and a 11% reduction in LDL. No significant variations in any of the lipid parameters monitored were observed in the placebo group. Treatment with simvastatin or gemfibrozil in hypertensive patients in hydrochlorothiazide monotherapy can reduce total cholesterol and LDL-cholesterol plasma levels, while significantly increasing HDL plasma levels compared to placebo. Simvastatin, however, resulted more efficient than gemfibrozil on total cholesterol or cholesterol fractions.

Stable angina pectoris and controlled ischemia: what causes the abnormalities in whole blood filterability?

The determinants of the altered whole blood filterability observed during coronary ischemia are still under discussion. Since no studies have been carried out to date on what exactly causes these alterations during the early stages of controlled ischemia in coronary heart disease, a model was set up using a bicycle ergometer test (with a 25 W increase every 2 minutes). Blood samples were taken from 48 stable angina pectoris patients and from a group of 28 matched controls before and immediately after exercise and 8 minutes later. Plasma viscosity, the filterability (through 5 microns diameter pore filters) of whole blood, erythrocytes, and polymorphonuclear and mononuclear leukocytes (separated by density gradient) were monitored. Alterations in whole blood filterability could be linked only to an impairment in polymorphonuclear cell filterability in those stable angina pectoris patients who reported chest pain and/or whose ST segment depression was greater than or equal to 2 mm.

Leucocyte rheology in controlled coronary ischaemia

Since no studies have been carried out on the exact origin of the alterations in white blood cell rheology during the early stages of controlled ischaemia in coronary arterial disease, a model was set up using a cycle ergometer test (with a 25 watts increase every 2 minutes). Blood samples were taken (before and after exercise and again 8 minutes later at recovery) from 18 patients with stable angina pectoris and a group of 22 matched controls. The filterability (through 5 micrometer diameter pore filters) of the polymorphonuclear leucocyte sub-population (separated by density gradient), the monocyte and lymphocyte sub-fractions (separated by adhesion to Petri dishes) as well as leucocyte activation (observed under a light microscope) were monitored. Our results showed that the total leucocyte count in patients and controls rose after exercise and was accompanied by a differential shift from the polymorphonuclear to the lymphocyte cells. The polymorphonuclear filterability rate increased significantly in patients when compared to their basal values at rest, and to the controls after exercise (+ 19.58%; P less than 0.002 vs basal values at rest; + 18.72%; P less than 0.002 vs controls). This increase persisted throughout the recovery period (+ 19.86%; P less than 0.002 vs basal values; and + 23.52% P less than 0.001 vs controls), indicating that a reduced polymorphonuclear leucocyte filterability can be associated with the first signs of ischaemia.

[Doppler echocardiography in atrial myxoma]

Two-dimensional echocardiography is the technique of choice for the diagnosis of atrial myxoma. In fact the Echo study allows the recognition of the presence of the tumor, and can show its dimensions, shape, implantation site and motility. However, it is not clear the role of Doppler echocardiography in the evaluation of atrial myxoma. This technique could be useful to recognize patients with more severe obstruction to atrioventricular flow due to large tumors. In 4 patients with large atrial myxomas (3 left and 1 right atrial myxoma) Doppler analysis of atrioventricular flow showed an apparent correlation between variation of trans-mitral or trans-tricuspid diastolic flow and symptoms (syncopal attacks). Only patients with an obstruction to atrioventricular flow and severely restricted calculated mitral or tricuspid orifice had syncopal attacks, at variance with patients without flow obstruction. Further studies on larger population will verify this apparent relation between atrioventricular flow obstruction and clinical symptoms in patients with large atrial myxoma.

[Multicenter clinical study of the antihypertensive activity of lisinopril]

One-hundred patients suffering from slight-moderate hypertension (53 m, 47 f, aged between 18 and 78, average 49.08) have been studied in order to assess the effectiveness and tolerance of lisinopril ("Zestril", ICI-Pharma), a new ACE inhibitor in a single daily administration at doses of between 10 and 80 mg in relation to pressure values. Monotherapy with Lisinopril proved effective in 84 patients (88.4%), in 74 of whom (7.9%) pressure values were returned to normal. 11 patients (11.6%) did not respond to treatment. In most cases, the result was obtained with a dose of 20 mg in a single administration (32.6%). The incidence of side-effects was limited and in no case required the withdrawal of the drug.

Antihypertensive efficacy and tolerability of captopril in the elderly: comparison with hydrochlorothiazide and placebo in a multicentre, double-blind study

In this study we compared the antihypertensive efficacy and tolerability of captopril at 25 mg twice daily, hydrochlorothiazide (HCTZ), 12.5 mg twice daily and placebo in a multicentre, double-blind, randomized study that included 152 essential hypertensive patients (77 males, 75 females, 87 WHO stage I, 65 WHO stage II, aged 69 +/- 4 years, mean +/- s.d.). Supine and standing blood pressure were similarly reduced by captopril and HCTZ (P less than 0.01 for both compared with placebo). The heart rate did not change. Captopril (25-30 mg twice daily) and HCTZ (12.5 mg twice daily), alone or in combination, maintained their antihypertensive effect during a 24-week single-blind follow-up study. During the follow-up, diastolic blood pressure remained less than 100 mmHg in seven essential hypertensives on placebo, in 45 on captopril and in 25 on HCTZ. Side effects were observed in seven essential hypertensives during placebo (treatment withdrawn in two), in eight during HCTZ and in three during captopril. Serum potassium was reduced (P less than 0.05) and uric acid was increased (P less than 0.01) only during HCTZ. We conclude that captopril and HCTZ have similar antihypertensive efficacy in the elderly; however, captopril appears to be better tolerated.

A multicenter trial of low dose captopril administered twice daily in patients with essential hypertension unresponsive to beta blocker-diuretic treatment

Two hundred and one patients with essential hypertension, whose supine diastolic blood pressure (SDBP) was greater than or equal to 95 mmHg following 2 weeks of treatment with the optimal dose of a beta blocker-diuretic combination (Phase 1), were randomly assigned to the addition of either 25 or 50 mg captopril BID for 6 weeks (Phase 2). At the end of Phase 2, the dose of captopril was doubled in the patients not normalized (SDBP greater than or equal to 95 mmHg) and maintained in the others (SDBP less than 95) for an additional 4 weeks (Phase 3). At the end of Phase 3, the beta blocker was withdrawn in the normalized (SDBP less than 95 mmHg) patients, and captopril plus diuretic was given for 4 weeks (Phase 4). The addition of captopril at either dose level led to a significant fall (p less than 0.01) in standing and supine diastolic and systolic blood pressure after the first 2 weeks of treatment. There was no significant difference in response between the two dose levels of captopril. At the end of Phase 2, 59.4% and 55.8% of patients, respectively, assigned to 25 and 50 mg captopril BID, were normalized. Doubling the dose of captopril (Phase 3) led to approximately an additional 30% of patients being normalized. At the end of Phase 4 (captopril plus diuretic) the SDBP was still less than 95 mmHg in 63% of patients, whereas it was increased in the others. Side effects were noted in 10 patients (5%). The incidence was similar in each treatment group, and a total of four patients (2%) were withdrawn due to side effects.

High prevalence of septal thickness overestimation in hypertensive subjects and controls

The aim of our study was to assess the frequency of important problems in the ultrasonic estimate of septal thickness as a consequence of multiple endocardial lines inside the septum in echocardiographic tracings of otherwise good technical quality. We performed an echocardiographic study in a population composed of 311 subjects (131 essential hypertensive subjects and 180 normotensive healthy controls) by using M-mode echocardiography under two-dimensional control, according to the recommendations of the American Society of Echocardiography. We observed the presence of one or more continuous lines inside the septum, each of them simulating an endocardial border and thus producing the appearance of two or more superimposed septal thicknesses differing by 2 mm or more in greater than 50% of the subjects (54% normotensive and 56% hypertensive). Furthermore, within the group of subjects with multiple septal lines, we found the disappearance of at least one of the farthest linear echoes, with resulting septal thinning of almost 2 mm in 58% of the normotensive and 61% of the hypertensive subjects. These findings suggest the need for caution when interpreting echocardiographic measurements of left ventricular septal thickness. We suggest that in the presence of multiple lines inside the septum, the echocardiographic examination should be continued up to the appearance of the thinnest septal image, possibly devoid of multiple lines inside the septum.

Similarities and differences in the antihypertensive effect of two calcium antagonist drugs, verapamil and nifedipine

The short- and long-term effects of two calcium channel blocking drugs, verapamil and nifedipine, on blood pressure, heart rate, plasma catecholamines, plasma renin activity, plasma volume and cardiac performance (echocardiography) were studied in essential hypertensive patients and in normal subjects. Verapamil, 160 mg orally, reduced blood pressure within 60 minutes in 22 hypertensive patients, but not in 12 normotensive subjects. Nifedipine, 10 mg sublingually, reduced blood pressure within 15 minutes in 19 hypertensive patients, but not in 7 normotensive subjects. Plasma noradrenaline was significantly increased both in normal subjects and in hypertensive patients only after nifedipine was administered. Verapamil (80 mg three times a day) first, and nifedipine (10 mg three times a day) thereafter, or vice versa, were given to 12 hospitalized hypertensive patients on a fixed sodium and potassium intake; the drugs produced similar blood pressure reductions, but heart rate and plasma catecholamines were increased only after nifedipine (p less than 0.05). Neither drug affected plasma volume, aldosterone or plasma renin activity. Long-term ambulatory treatment with verapamil (80 or 160 mg three times a day for 2 to 4 months) or nifedipine (10 mg three times a day for 2 months) produced changes in all variables that were similar to those observed in the hospital (controlled) study. Shortening fraction was significantly increased after nifedipine (p less than 0.05) but no change was observed after verapamil. In conclusion, blood pressure is effectively reduced by both verapamil and nifedipine; an appreciable adrenergic stimulation may be caused by nifedipine, but usually not by verapamil, and fluid retention, renin release or myocardial depression is not observed during verapamil or nifedipine treatment.

Age and responses to isometric exercise in hypertension: possible predictors of the antihypertensive effect of diuretics and beta-blockers

In a multicenter, randomized, double-blind study, 108 hypertensive patients were treated with either chlorthalidone 25 mg or slow-release metoprolol 200 mg both given once daily over 4 weeks. Blood pressure and heart rate at rest and at the peak of an isometric exercise test (30% of maximal voluntary contraction for 3 min) were recorded at random and at the end of the study. Both treatments induced a significant (p less than 0.01) blood pressure reduction at rest and at the peak exercise, 50.0% of patients on chlorthalidone and 59.2% on metoprolol, respectively, having a lying diastolic blood pressure less than 95 mmHg. A weak but significant (p less than 0.001) positive correlation was found between age and change in systolic and diastolic blood pressure after chlorthalidone. Such a relationship was absent in the metoprolol group, where a significant (p less than 0.01) positive correlation was found between diastolic pressure rise from rest to the peak exercise at randomization, and the reduction in resting diastolic pressure at the end of the study. Treatments were well tolerated, only a decrease (p less than 0.05) in serum potassium (from 4.4 to 4.0 mEq/l) in the chlorthalidone group was observed. Results suggest that age may influence the antihypertensive response to chlorthalidone, while diastolic pressure rise in isometric exercise may predict the degree of pressure response to sustained beta-adrenergic blockade with metoprolol.

Ventilatory effects of selective beta 1-(prenalterol) or beta 2-(salbutamol) adrenoceptor agonism in man

We compared the ventilatory effects of prenalterol (beta 1-selective adrenoceptor agonist) with those of salbutamol (beta 2-selective adrenoceptor agonist) in 6 healthy volunteers. Two intravenous doses of prenalterol (1 mg/60 min, 2 mg/60 min) and of salbutamol (300 micrograms/60 min, 600 micrograms/60 min) were given in random order in 4 separate sessions of 60 minutes each. Pulmonary ventilation per minute (V'E) increased only on the high dose of salbutamol. Mouth occlusion pressure (P0.1) did not vary either on prenalterol or on salbutamol. Only the high dose of salbutamol induced (1) an increase in tidal volume (VT) without changes in respiratory rate (RR), (2) an increase in mean inspiratory flow (VT/Ti) without changes in the fraction of inspiratory time to total cycle duration (Ti/Ttot). During forced expiration, salbutamol elicited a small bronchodilating effect at the level of both large (FEV1, FEF25-75, FEF50) and small (FEV3, FEF75-85, FEF75) airways. Prenalterol induced a very small dilatation of the large airways, and a somewhat more pronounced effect at the level of the small airways. Neither the indexes of ventilatory pattern nor those of bronchial tone showed any statistical or biological differences between values on prenalterol and values on salbutamol. However, both the former and the latter indexes showed a trend to be higher on salbutamol than on prenalterol. Results suggest that salbutamol-induced increase in pulmonary ventilation per minute in subjects without bronchial obstruction is likely the result of a reduced bronchomotor tone at rest, leading to an increase in tidal volume because of the rise in the VT/Ti ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular hypertrophy regression in hypertensive patients treated with metoprolol

The long-term effects of metoprolol monotherapy, 100 mg b.i.d., for 16-18 months, were investigated in 8 previously untreated essentially hypertensive patients (resting blood pressure greater than 155/95 mmHg) and echocardiographic evidence of left ventricular hypertrophy (LVH) (left ventricular mass by Penn Cube formula greater than 215 g). Echocardiographic studies, according to the American Society of Echocardiography recording techniques and measurements criteria, were performed before starting treatment and at the end of follow-up. Metoprolol induced a decrease in systolic and diastolic blood pressure and heart rate, accompanied by a reduction of interventricular septum and posterior wall thickness (from 1.21 cm to 1.10 cm, and from 1.15 cm to 1.06 cm, respectively), left ventricular mass index and mean wall stress. All these changes were significant (p less than 0.01). Cardiac index decreased from 3017 ml/m2 to 2632 ml/m2 (p less than 0.01), mostly because of the reduction in the heart rate. In fact, stroke index, ejection fraction and fractional shortening all slightly increased during treatment in respect to pre-treatment values. Plasma renin activity fell from 1.45 ng/ml/h to 0.81 ng/ml/h (p less than 0.01), whereas both plasma noradrenaline and adrenaline concentration at rest did not change. Results indicate that in essentially hypertensive patients who have already developed LVH as a consequence of the hypertension, a long-term metoprolol therapy can successfully induce a reversal of LVH together with an effective blood pressure control, without noticeable adverse effects of changes in cardiac performance.

Noninvasive assessment of chronotropic and inotropic response to preferential beta-1 and beta-2 adrenoceptor stimulation

The relative chronotropic and inotropic activity of preferential beta 1- and beta 2-adrenoceptor stimulation was investigated in seven healthy male subjects in a randomized within-subject, single-blind study. Two doses of beta 1-selective agonist prenalterol (1 mg/hr or 2 mg/hr) and of beta 2-selective agonist salbutamol (300 micrograms/hr or 600 micrograms/hr) were infused intravenously in four separate sessions, with intervals of at least 48 hr between sessions. At each session cuff blood pressure and heart rate (HR) were measured and some hemodynamic information on the inotropic state were derived by echocardiography. Both prenalterol and salbutamol induced increases in HR, but tachycardia was greater after salbutamol, whereas the positive inotropic response to beta-stimulation was greater after prenalterol. At comparable HR rises (prenalterol, from 66.0 +/- 5.5 to 72.2 +/- 4 bpm; salbutamol, from 64.6 +/- 6 to 70.0 +/- 7 bpm), inotropic response seemed to be greater after prenalterol than after salbutamol (systolic blood pressure [SBP]: 133.5 +/- 8 and 120.7 +/- 8 mm Hg; mean velocity of circumferential fiber shortening [Vcf]: 1.54 +/- 0.13 and 1.31 +/- 0.12 c/s; ejection fraction [EF]: 72.4% +/- 5% and 69.5% +/- 4%; stroke index: 47.4 +/- 4 and 41.7 +/- 3 ml/m2). In presence of a chronotropic effect (HR from 64.6 +/- 6 to 70.0 +/- 7 bpm), the low salbutamol dose did not induce any changes in the indices of inotropism (SBP: from 119.2 +/- 6 to 120.7 +/- 8 mm Hg; mean Vcf: from 1.28 +/- 0.11 to 1.31 +/- 0.12 c/s; EF: from 68.1% +/- 5% to 69.5% +/- 4%; stroke index: from 40.2 +/- 3 to 41.7 +/- 3 ml/m2.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma norepinephrine and left ventricular hypertrophy in systemic hypertension

The relations between some pressure and humoral factors, and some echocardiographic indexes of left ventricular (LV) hypertrophy were studied in 64 patients with essential hypertension. Fifty-seven percent of these patients showed echocardiographic evidence of LV hypertrophy (LV mass greater than 215 g). Multivariate stepwise regression analysis showed that only mean blood pressure (BP) and circulating norepinephrine (NE) levels were significantly related to LV mass index in the group of patients with LV hypertrophy. However, mean BP was the only factor related to LV mass index in the subgroup of patients with LV hypertrophy and plasma NE within the normal laboratory range, whereas NE was the sole factor related to LV mass index in the subgroup with LV hypertrophy and abnormally elevated NE levels (greater than mean + 2 standard deviations of the normal laboratory range). Correlation of LV mass index vs NE was -0.35 (not significant) in the former group of patients and 0.89 (p less than 0.01) in the latter group. NE showed no relation with the echocardiographic variables in the hypertensive patients without LV hypertrophy; in this group, diastolic BP was the only factor related to LV mass index. Circulating NE levels were slightly higher in patients with LV hypertrophy (213 +/- 68 ng/liter) than in those without LV hypertrophy (187 +/- 46 ng/liter), but differences were not significant when adjusting NE for age. Plasma renin activity was not dissimilar in the absence or presence of hypertrophy. In conclusion, our findings suggest that NE might be associated with pressure factors in regulating LV hypertrophy development only in a subgroup of hypertensive patients characterized by echocardiographic LV hypertrophy and abnormally elevated circulating NE levels.

[Hemodynamic and humoral changes in long-distance athletes]

Cardiac anatomy and function, and some biohumoral parameters, have been examined in 11 long-distance olympic runners, and in 11 healthy untrained control subjects. Echocardiographic methods and computed reading of tracings were adopted. Long-distance runners were also studied within 2 minutes after the end of a 30 Km race. At rest, the athletes had thicker interventricular septa and, posterior walls, higher left ventricular mass index, larger end-diastolic dimensions, cardiac index and stroke index compared to the untrained subjects (all P less than 0.01). Resting heart rate was lower in runners (P less than 0.01). In runners, competitive exercise test induced significant haemodynamic changes (increases in cardiac index, heart rate, stroke index, ejection fraction [all P less than 0.01], decreases in end-systolic dimensions and peripheral vascular resistance [both P less than 0.01]). After exercise, runners showed massive increases both of norepinephrine and epinephrine serum levels (measured in 4 subjects), an increase, in haematocrit and plasma glucose concentration, and a decrease in plasma potassium concentration (all P less than 0.01). In conclusion, olympic long-distance runners have increased cardiac dimensions and wall thickness at rest as compared with healthy untrained subjects matched for age and resting blood pressure. In the former group, a competitive long-distance test results in marked haemodynamic changes, with massive increase in plasma catecholamine concentration and concomitant reduction in plasma potassium concentration. This combination is potentially hazardous, and warrants further investigation.

Acute effects of beta 1 agonism with prenalterol on catecholamine circulating levels in patients with congestive heart failure

The effects of a single intravenous infusion of prenalterol, a beta 1 selective agonist, on haemodynamics (echocardiography) and venous plasma catecholamine concentration were studied in 8 patients with severe congestive heart failure. In these patients, age-adjusted plasma norepinephrine (NE) and epinephrine (E) levels before prenalterol infusion were higher compared to values found in 10 control healthy subjects (both P less than 0.01). In heart failure patients, circulating NE levels were not dissimilar in 2 samples drawn 60 and 0 minutes before commencing prenalterol infusion (772.0 +/- 131 ng/l [mean +/- SD] and 775.5 +/- 130.0 ng/l respectively). Prenalterol induced a significant improvement in the cardiac index, stroke index, ejection fraction and velocity of circumferential fiber shortening, associated with a moderate but significant decrease in peripheral vascular resistance. All these changes persisted for 60 minutes after the end of infusion. Circulating NE levels were 604.0 +/- 125 ng/l at 60 min. after start of infusion (P less than 0.01 vs pre-infusion levels) and 526.1 +/- 108 ng/l at 60 min. after the end of infusion (P less than 0.01 vs pre-infusion levels). Plasma E showed a slight decrease, which did not attain statistical significance. Heart rate and diastolic blood pressure remained unchanged during and after infusion, while systolic blood pressure increased by 10-15 mmHg during and after infusion. We conclude that a single 1-hour prenalterol infusion in patients with severe congestive heart failure induces an haemodynamic improvement associated with a reduction of previously elevated circulating NE levels. This reduction could indicate a lowering in the intensity of the afferent stimulus for the reflex sympathetic overactivity.

Echocardiographic left ventricular hypertrophy as related to arterial pressure and plasma norepinephrine concentration in arterial hypertension. Reversal by atenolol treatment

We tried to assess relationships between echocardiographic left ventricular hypertrophy (LVH), arterial pressure levels, and plasma norepinephrine concentration (NE) in 20 previously untreated stable hypertensive patients with LVH, and in 11 healthy normotensive control subjects. Interventricular septal (IVS) thickness, posterior wall (PW) thickness, and left ventricular mass index (LVMI) were related to arterial pressure levels and to NE by univariate and multivariate regression analyses. In addition, after 18 months of monotherapy with atenolol (carried out in nine of 20 patients), the relationship between echocardiographic changes and degree of pressure reduction was tested. Before treatment, PW thickness weakly correlated with systolic (r = 0.55; p less than 0.01) and mean (r = 0.50; p less than 0.05) arterial pressure. IVS thickness weakly correlated with NE (r = 0.53; p less than 0.05). On this relatively small sample, multivariate regression analysis showed an association of both IVS thickness (R = 0.57; p less than 0.05) and PW thickness (R = 0.58; p less than 0.05) with mean arterial pressure (MAP) and NE. After atenolol, there was a reduction in IVS thickness (1.15 to 1.02 cm; p less than 0.01), PW thickness (1.08 to 0.99 cm; p less than 0.01), and LVMI (136.3 to 113.8 g/m2; p less than 0.01), besides a significant reduction in blood pressure and heart rate. The degree of pressure reduction induced by treatment did not correlate the change in IVS or PW thickness. In contrast, the change in diastolic and mean arterial pressure positively correlated the change in LVMI (r = 0.72 and r = 0.75, respectively; both p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Low-dose captopril therapy in mild and moderate hypertension. Randomized comparison of twice daily vs three times daily doses

We have investigated the antihypertensive activity of relatively low daily doses of captopril in patients with mild and moderate arterial hypertension. In a first trial, at the end of a 2-week placebo washout period, 18 patients with essential hypertension WHO Stage I or II were treated with captopril, 25 mg three times daily (t.i.d.), 25 mg twice daily (b.i.d.), 50 mg t.i.d., and 50 mg b.i.d., according to a randomized within-patient open design, with each regimen lasting for a 2-week period. In a second trial, 12 hypertensive patients not adequately controlled by chlorthalidone 25 mg daily as monotherapy (supine diastolic blood pressure at rest greater than 95 mm Hg), continued the diuretic treatment in combination with captopril, 25 mg t.i.d. and 25 mg b.i.d. according to a randomized within-patient open design. Analysis of variance did not reveal differences between the four captopril dosing schedules (1st trial), or between the two captopril dosing schedules (2nd trial). Both the patients on captopril monotherapy (1st trial) and those cotreated with chlorthalidone (2nd trial) showed lower systolic and diastolic blood pressure values on each captopril regimen compared to prerandomization values (all p less than 0.01). No relevant unwanted effects were noted. We conclude that in patients with mild or moderate essential hypertension, either untreated or resistant to chlorthalidone, captopril is effective in reducing blood pressure even at daily doses not exceeding 150 mg, without differences between a t.i.d. and a b.i.d. dosing schedule.

Relationships between plasma catecholamines, renin, age and blood pressure in essential hypertension

The aim of this study was to examine the interrelationships between age, plasma catecholamines, plasma renin activity (PRA) and blood pressure in essential hypertensive (EH) patients. PRA, plasma noradrenaline (NA) and adrenaline (A) were measured in 76 consecutive EH patients (WHO stages 1-2, aged 24-66 years) and in 28 normotensive subjects (aged 25-64 years) studied at rest in supine position after 5 days of normal fixed sodium and potassium intake. Both plasma NA and A were slightly but significantly higher in EH patients (p less than 0.05). While no relationship was found between the various parameters in normotensive subjects, in EH patients, particularly those at WHO stage 2, plasma NA was directly related to mean blood pressure (MBP) (p less than 0.001) and PRA (p less than 0.01). Plasma A was weakly related to MBP (p less than 0.05); PRA was inversely related to age (p less than 0.01) but no relationship was found between NA or A and age. Partial correlation analysis confirmed all these relationships. In fact, NA was related to MBP also considering constant PRA (p less than 0.001) or age (p less than 0.001), and NA was related to PRA also considering constant MBP (p less than 0.01) or age (p less than 0.001). Acute pharmacological alpha- and beta-blockade, with labetalol 100 mg i.v., induced a reduction of MBP which was directly related to basal plasma NA (p less than 0.001). These results support the view that in EH the sympathetic nervous system might be in part responsible for PRA levels and for the severity of hypertension.