Three weekly injections (TWI) of low-dose growth hormone (GH) restore low normal circulating IGF-I concentrations and reverse cardiac abnormalities associated with adult onset GH deficiency (GHD)

GH replacement therapy given 3 times weekly (TWI) and adjusted to allow serum IGF-I concentrations in the mid-normal range for sex and age has been shown to be as effective as the daily regimen in improving lipid profile, body composition, bone mass and turnover in adult GH deficient (GHD) patients. Only one study has investigated so far the short-term (6 months) effect of a fixed weight-based TWI dosing schedule on heart structure and function in childhood onset (CO) GHD patients, whereas such a schedule in adult onset (AO) GHD patients has not been studied as yet. Aim of this study was to investigate whether a 1-yr low-dose titrated TWI GH-replacement regimen aimed at achieving and maintaining IGF-I levels within the low normal limits for age and sex is able to affect cardiovascular and heart parameters in a group of AO GHD patients. Eight adult patients (4 women and 4 men, age 35.8 +/- 3.37 yr, body mass index, BMI, 28.7 +/- 2.62 kg/m2) with AO GHD were included in the study, along with 10 healthy subjects, matched for age, sex, BMI and physical activity (6 women and 4 men, age 35.2 +/- 4.05 yr, BMI 28.4 +/- 2.34 kg/m2). M- and B- mode ecocardiography and pulsed doppler examination of transmitral flow were performed in GHD patients at baseline and after 3 and 12 months of GH therapy (mean GH dose 6.7 +/- 0.8 microg/kg/day given thrice a week), while normal subjects were studied once. Treatment with GH for 1 yr induced a significant increase in left ventricular (LV) diastolic and systolic volumes (+11.1 and +16.5%, respectively). Systolic LV posterior wall thickness and LV mass were increased (+10.2 and +7.7%, respectively) by GH administration. Systemic vascular resistance was significantly decreased by 1-yr GH therapy (-13.8% after 1 yr), while stroke volume, cardiac output and cardiac index were increased (+9.4, +11.6 and + 11.9%, respectively). LV end-systolic stress was decreased at the end of GH therapy (-11.2%). E and A wave, significantly reduced at baseline, were increased by 1 yr of GH therapy (+23.3% and +28.1%, respectively); likewise, the abnormally high E peak deceleration time was partially reversed by GH administration (-10.7%). Our study, though conducted in a small sample size, demonstrates that a TWI GH treatment schedule is able to reverse the cardiovascular abnormalities in AO GHD patients and to improve body composition and lipid profile. The maintenance of circulating IGF-I concentrations within the low normal range allows to avoid most of the side-effects reported with higher GH doses while being cost-effective and improving the patient's compliance.

Different baseline sympathovagal balance and cardiac autonomic responsiveness in ischemic and non-ischemic congestive heart failure

BACKGROUND

A profound autonomic unbalance is present in heart failure: its correlation with the etiology of the disease has never been investigated.

AIMS

We characterized the sympatho-vagal balance and autonomic responsiveness of 42 patients (21 with ischemic heart failure, 21 with idiopathic dilated cardiomyopathy). Patients had comparable NYHA class, ejection fraction, exercise pVO(2), exercise ventilatory response, incidence of beta-blocking treatment. None showed periodic breathing or nocturnal arterial desaturation.

METHODS

Heart rate variability was assessed in the time and frequency domain during: (1) 10 min of quiet supine resting and free breathing; (2) 10 min of regular breathing at a frequency of 20 acts/min (=parasympathetic stimulus); and (3) 10 min of active standing (=sympathetic stimulus). The ratio of the low- to high-frequency components of each autospectrum obtained in the frequency domain (LF/HF) was used as an index of sympathovagal balance.

RESULTS

Patients with ischemic heart failure had a greater baseline sympathetic activation (higher LF/HF) than those with idiopathic dilated cardiomyopathy, maintaining some parasympathetic responsiveness as well (reduced LF/HF with regular breathing).

CONCLUSIONS

There is a distinct autonomic control according to the etiology of heart failure, a finding that may help understanding its pathophysiology, and could be useful in the clinical management of patients.

Long-term lifestyle changes maintain the autonomic modulation induced by rehabilitation after myocardial infarction

The altered autonomic balance observed after myocardial infarction is shifted toward a higher parasympathetic tone by rehabilitation. This effect persists after 1 year, however we observed a discrete variability in the long-term sympathovagal balance among patients. We postulated that such variability derives from the disparate adherence of patients to lifestyle prescriptions regarding exercise continuance and smoking avoidance. To test this hypothesis, we reviewed the data of 40 patients, who completed with a favourable autonomic modulation the initial rehabilitation phase after myocardial infarction and underwent the annual follow-up. One year after infarction, 23 patients complied to the advice about regular exercise and smoking avoidance (adherent, Group 1); 17 did not (non-adherent, Group 2). Groups were similar for age, site of infarction, left ventricular function, stress test duration and therapy. The ratio LF/HF, derived from the power spectral density of RR intervals variability, was used as an index of the sympathovagal balance. It was obtained from 15 min of ECG at rest, assessed 1 month after MI (baseline), and repeated 3 months (rehabilitation) and 1 year (follow-up) afterwards. Rehabilitation increased parasympathetic tone in all patients, reducing LF/HF by 33%. At follow-up, this potentially favourable autonomic profile persisted only in Group 1 patients. In conclusion, after a first myocardial infarction, the persistence of the potentially beneficial effect of rehabilitation on the sympathovagal balance depends on the compliance to the lifestyle changes proposed during the initial phase.

Markers of electrical instability in hypertensive patients with and without ventricular arrhythmias. Are they useful in identifying patients with different risk profiles?

BACKGROUND

Markers of electrical instability of the ventricular myocardium, namely abnormal repolarization and late potentials, are frequently observed in patients with hypertension when both ventricular arrhythmias and left ventricular hypertrophy are present. This information cannot be extrapolated to the population of hypertensive patients with ventricular arrhythmias but without left ventricular hypertrophy.

OBJECTIVE

To evaluate QT duration, QT dispersion and the incidence of ventricular late potentials in patients with essential hypertension, already on anti-hypertensive therapy, both with and without non-sustained ventricular arrhythmia.

DESIGN

The study population consisted of 49 patients with essential hypertension who were compared to 89 control normotensive subjects both with and without frequent (> 30 per h) ventricular ectopic beats (VPBs). Patients were divided into four groups: (1) hypertensive patients without VPBs (H, n = 19), (2) hypertensive patients with VPBs (HA, n = 30), (3) normotensive subjects without VPBs (C, n = 28), and (4) normotensive subjects with VPBs (CA, n=61).

METHODS

Echocardiographic parameters, QT interval, QT dispersion and signal-averaged ECG were evaluated without withdrawing anti-hypertensive drugs.

RESULTS

In no case was left ventricular hypertrophy documented. The number of VPBs during 24 h Holter recording (median 11 343 versus 7617) and the incidence of repetitive VPBs (37 versus 46% of patients) were similar in the two groups of patients (HA versus CA). Signal-averaged ECG parameters were normal and not different between the four groups. QT interval was longer in hypertensive patients compared to controls irrespective of the presence of VPBs. QT dispersion was slightly greater in subjects with VPBs, both hypertensive and normotensive, compared to subjects without arrhythmias.

CONCLUSIONS

In patients with hypertension well-controlled by drug therapy and without left ventricular hypertrophy, frequent VPBs are not associated with markers indicating an electrophysiological substrate for re-entrant arrhythmias. However, QT prolongation suggests the persistence of a higher risk of cardiovascular mortality that is independent of the presence of VPBs.

Relationship between baseline sympatho-vagal balance and the autonomic response to cardiac rehabilitation after a first uncomplicated myocardial infarction

BACKGROUND

After a first uncomplicated myocardial infarction, cardiac rehabilitation increases the parasympathetic tone, in a direction linked to a reduced risk of sudden cardiac death. This change in sympatho-vagal balance may be related to other clinical variables. The aim of this study was to define the factors implicated in determining the autonomic response to cardiovascular rehabilitation after myocardial infarction.

METHODS

In 55 patients (39-80 years) we evaluated the modulation of the autonomic profile induced by 8 weeks of rehabilitation: we analyzed the changes in pNN50 derived from time-domain analysis (deltapNN50) and in the low frequency/high frequency (LF/HF) ratio derived from autoregressive power spectral analysis (deltaLF/HF). A control group of 15 patients not undergoing rehabilitation was also studied. Variables considered at 4 weeks postinfarction and related to deltapNN50 and deltaLF/HF ratio were: age, site of myocardial infarction, previous thrombolysis, ejection fraction, stress test duration, baseline LF/HF ratio.

RESULTS

Patients not undergoing rehabilitation did not change their autonomic profile. On the contrary, rehabilitation induced a higher vagal tone (pNN50 from 6.5 +/- 1.5 to 16.2 +/- 3.1; LF/HF ratio from 8.3 +/- 5.2 to 5.1 +/- 2.9, p < 0.05). Eleven patients (20%) had baseline LF/HF ratio exceeding the mean value by 1.5 SD (19.4 +/- 1.4): in this subgroup, pNN50 was very low. In these patients, rehabilitation increased pNN50 and decreased LF/HF ratio. Indeed, both deltapNN50 and deltaLF/HF ratio were significantly related to their baseline values (p < 0.001), even considering thrombolysis, site of myocardial infarction, age, and beta-blocker therapy.

CONCLUSIONS

After a first uncomplicated myocardial infarction, sympatho-vagal balance may be very disturbed in some patients, despite a preserved ventricular function, good exercise capability and beta-blockers. These patients should be encouraged to undergo rehabilitation, since the significant improvement in the parasympathetic tone may protect them against subsequent arrhythmic events.

Increased left ventricular dimensions in patients with frequent nonsustained ventricular arrhythmia and no evidence of underlying heart disease

INTRODUCTION

To test the hypothesis that frequent nonsustained ventricular premature beats (VPBs) in patients without underlying heart disease are the first marker of mild systolic dysfunction of the left ventricle, we evaluated whether a subclinical abnormality of left ventricular function and/or an intraventricular conduction defect was present at the first clinical documentation of the arrhythmia.

METHODS AND RESULTS

We compared 57 patients (mean age 46 +/- 14 years) with > 30 VPBs/hour and no heart disease (A) to 32 healthy volunteers (mean age 42 +/- 12 years) without arrhythmia (B). Left ventricular echocardiographic parameters and signal-averaged ECG were evaluated. Filtered QRS duration (98 +/- 10 msec in A vs 98 +/- 7 msec in B) was similar in the two groups. End-diastolic left ventricular diameter (EDLVD) was 50 +/- 6 mm in A versus 47 +/- 3 mm in B (P < 0.005); 15 patients (26%) and none of the controls had EDLVD > or = 55 mm (P < 0.005). Filtered QRS interval was longer in the subgroup of patients (n = 15) with increased EDLVD (> or = 55 mm) compared with the subgroup (n = 42) with EDLVD < 55 mm (106 +/- 9 msec vs 95 +/- 9 msec; P < 0.001) and was related to greater left ventricular mass.

CONCLUSION

We documented a subclinical but significant increase of left ventricular dimensions that suggests that frequent VPBs may be an initial marker of mild systolic dysfunction of the left ventricle. However, an effect of VPBs per se in modifying left ventricular dimensions cannot be excluded.

Effects of cardiac rehabilitation and beta-blocker therapy on heart rate variability after first acute myocardial infarction

After acute myocardial infarction (AMI), rehabilitation with physical training increases parasympathetic tone. It is unknown whether such a favorable effect of exercise on the sympathovagal balance interacts with effects of other widespread therapies, such as beta blockers. In 53 patients after a first, uncomplicated AMI, we studied the combined short- and long-term influence on heart rate variability (HRV) of rehabilitation and beta blockade. Patients were divided into 3 groups: group 1 (n = 19) underwent rehabilitation with physical training; group 2 (n = 20) was taking beta blockers and underwent rehabilitation; group 3 (n = 14) was taking beta blockers and did not enter the rehabilitation program for logistic reasons. Patients were similar as to age, site of infarction, ejection fraction, left ventricular diameter, and baseline stress test duration. Measures of HRV (obtained from a 15-minute resting electrocardiogram) were the standard deviation of the mean RR interval (RRSD), the mean squared successive differences (MSSD), the percent of RR intervals differing >50 ms from the preceding one (pNN50), the low-(LF) and high-(HF) frequency components of the autoregressive power spectrum of the RR intervals and their ratio (LF/HF). Four weeks after AMI, there was less sympathetic predominance in groups 2 and 3 (i.e., patients taking beta blockers [p <0.05]). Rehabilitation modified HRV in groups 1 and 2 (p <0.05), with signs of increased parasympathetic tone (group 1: MSSD +25%, pNN50 +69%, LF/HF -40%; group 2: MSSD +41%, pNN50 +48%, LF/HF -39%). These changes persisted in the long term. In group 3, HRV was unchanged over time. Hence, after AMI, the effects of rehabilitation and beta blockers on HRV are not redundant: their association induces a more favorable sympathovagal balance, accelerating the recovery of a normal autonomic profile.

Adults with childhood-onset growth hormone deficiency: effects of growth hormone treatment on cardiac structure

OBJECTIVES

To evaluate the effects of growth hormone deficiency (GHD) and of growth hormone (GH) therapy on cardiac structure in adults with childhood-onset GHD.

SETTING

Out-patient clinic in the Italian Institute for Auxology, Milan.

SUBJECTS

Eight adults with childhood-onset GHD and eight healthy controls, matched for sex, age, exercise and body mass index.

INTERVENTIONS

Recombinant GH (Saizen Serono, Italy), administered in a conventional dose of 0.5 IU kg-1 week-1 for 6 months.

MAIN OUTCOME MEASURES

Cardiac structure parameters, evaluated by two-dimensional, M-mode and Doppler echocardiograms, and stress test, by means of a modified Bruce protocol with a bicycle ergometer, were determined before and after 6 months GH therapy.

RESULTS

Before treatment, mean (+/- SE) intraventricular septal thickness (IVST: 7.1 +/- 0.2 mm), LV posterior wall thickness (LVPT: 5.2 +/- 0.1 mm), LV mass (LVM: 94.6 +/- 5.0 g), LV mass index (LVM/body surface area, LVMI: 65.1 +/- 3.0 g m-2) and left ventricular end-diastolic diameter (LVED: 41.4 +/- 0.6 mm) of patients were significantly lower (P < 0.01) than in controls, whilst LV end-systolic diameter (LVES) of patients (25.5 +/- 0.7 mm) was similar to controls (27.5 +/- 0.7). GH treatment significantly (P < 0.01) increased LVPT (6.8 +/- 0.2 mm), LVM (111.6 +/- 4.6 g) and LVMI (80.5 +/- 3.5 g m-2); no significant changes were observed in LVED, LVES and IVST values. The stress test showed a significant improvement of cardiac performance, as demonstrated by the reduction of blood pressure x heart rate product at the same workload (basal: 32,722.5 +/- 897.4 vs. after: 25,574.6 +/- 439.7).

CONCLUSIONS

GH plays a role in the maintenance of a normal cardiac structure in adulthood. The present study suggests that GH treatment might be able to improve the cardiac structure of patients with childhood-onset GHD.

Short and long term effects of exercise training on the tonic autonomic modulation of heart rate variability after myocardial infarction

We studied the effects of cardiac rehabilitation on the sympathovagal control of heart rate variability in 30 patients after a first, uncomplicated myocardial infarction. Twenty-two patients completed 8 weeks of endurance training (trained), while eight decided not to engage in the rehabilitation programme for logistical reasons, and were taken as untrained controls. Age, site of infarction, ejection fraction, ventricular diameter and stress test duration were similar in the two groups at baseline. Heart rate variability was evaluated 4 weeks after infarction before starting rehabilitation, and repeated 8 weeks and one year later in both trained and untrained patients. Measures of heart rate variability, obtained from both time- and frequency-domain analysis of a 15 min ECG recording in resting conditions, were as follows: mean RR interval and its standard deviation (RRSD), the mean square successive differences (MSSD), the percent of RR intervals differing > 50 ms from the preceding RR (pNN50), the low and high frequency components of the autoregressive power spectrum of the RR intervals and their ratio (LF/HF). At baseline, heart rate variability was similar in trained and untrained patients. In the short term (8 weeks after infarction), training increased RRSD by 25% (P < 0.01), MSSD by 69% (P < 0.01), pNN50 by 120% (P < 0.01), and reduced LF/HF ratio by 30% (P < 0.01). The effects persisted after one year in trained patients. In untrained patients, the autonomic control of heart rate variability did not change 8 weeks after myocardial infarction and was only slightly modified by time. Thus, exercise training, performed for 8 weeks after a myocardial infarction, modifies the sympathovagal control of heart rate variability toward a persistent increase in parasympathetic tone, known to be associated with a better prognosis. This may partly account for the favourable outcome of patients who undergo rehabilitation.

[Cardiac and vascular hypertrophy in juvenile borderline hypertension: echocardiographic and ultrasonographic study]

BACKGROUND

High resolution ultrasonography is a noninvasive technique that allows us to investigate the cardiovascular system, in particular the wall thickness and the lumen diameter of the arteries, with accuracy and reproducibility.

METHODS

We measured the intima-media thickness of the common carotid artery (CCA) and of its bifurcation (BIF) in 20 borderline hypertensive (age 24 +/- 4 years) and in 20 normotensive subjects (age 24 +/- 4 years), as a control group. Both carotid axes were scanned from different views (anterior, lateral, posterior) on a transversal and longitudinal section using a high resolution steerable linear array of 5 MHz. Carotid diameter and thickness were measured in the longitudinal section. CCA parameters were assessed 20 mm caudally to the flow divider.

RESULTS

In borderline patients blood pressure (147.8 +/- 10.5/90.7 +/- 6.6 mmHg) and left ventricular mass index (102.5 +/- 15.3 g/m2) were significantly higher than in normotensive subjects (blood pressure 120.5 +/- 11.5/78.0 +/- 5.4 mm Hg; left ventricular mass 90.5 +/- 14.3 g/m2). The intima-media thickness of both the CCA and BIF was significantly higher in borderlines than in normotensives (CCA 0.6 +/- 0.08 vs 0.4 +/- 0.05 mm, p < 0.001; BIF 0.7 +/- 0.08 vs 0.5 +/- 0.08, p < 0.001). In the whole population there was a statistically significant correlation between the carotid wall thickness and the left ventricular mass.

CONCLUSIONS

Our data show that ultrasonography provides direct evidence that in young borderline hypertensives the increased left ventricular mass is associated with vascular hypertrophy.

Effect of verapamil on atherosclerosis

Whether antihypertensive agents exert an antiatherosclerotic effect by blood pressure reduction or independently of their antihypertensive effect is clinically relevant. Animal studies have generally shown that the calcium antagonist verapamil has a preventive rather than a therapeutic antiatherosclerotic effect, which is independent of its antihypertensive effect. However, doses used in animal studies were much higher than those administered to humans and, in animals, the time of administration of verapamil coincided with the application of atherogenic stimulus. Human studies have given controversial results. Verapamil appears to effectively reduce the restenosis rate after coronary angioplasty. However, in patients with coronary stenosis who were undergoing bypass surgery, results were conflicting: a retrospective study provided positive results, while a prospective study gave negative results. An ongoing study investigating the effect of verapamil on the carotid arteries of hypertensive patients could help clarify the relationship between blood pressure reduction and the progression, regression or development of carotid lesions.

[Ultrasonographic evaluation of cardiac and vascular hypertrophy in patients with essential hypertension]

High resolution ultrasonography allows the accurate and reproducible measurement of thickness and lumen diameter of carotid arteries. We investigated Common carotid (CCA) and bifurcation intima-media thickness in 40 hypertensive patients, 20 without left ventricular hypertrophy (LVH) (age 42 +/- 10 years) and 20 with LVH (age 44 +/- 12 years), all free from other important cardiovascular risk factors. Both carotid axes were scanned from different views (anterior, lateral, posterior) on traversal and longitudinal section, using a high resolution steerable (HRS) 5.0 MHz linear array. Carotid diameter and thickness from longitudinal section were measured. CCA parameters were taken 20 mm caudally to flow divider. Using the B-mode as a guide we assessed LVH presence with M-mode technique when left ventricular mass index (LVMI) > or = 135 g/m2 for men and > or = 110 g/m2 for women. In hypertensive patients with LVH, left ventricular mass was significantly higher than in those without LVH (156 +/- 38 vs 98 +/- 10 g/m2, p < 0.01). Even blood pressure was significantly higher in hypertrophic group (172 +/- 21/108 +/- 9 vs 158 +/- 11/99 +/- 12 mmHg, p < 0.01), while there was no difference in serum glycemia, triglycerides, total and fractioned cholesterol levels. The intima-media thickness scanned in both CCA and bifurcation resulted significantly higher in hypertensives with LVH (CCA: 0.85 +/- 0.02 mm vs 0.65 +/- 0.02 mm; BIF: 0.93 +/- 0.04 mm vs 0.70 +/- 0.03 mm, p < 0.01). We also noticed a statistically significant correlation between carotid wall thickness and left ventricular mass index.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic and ultrasonographic evaluation of cardiac and vascular hypertrophy in patients with essential hypertension

High-resolution ultrasonography is a noninvasive technique that allows to investigate the cardiovascular system, in particular the wall thickness and the lumen diameter of the arteries with accuracy and reproducibility. We measured the intima-media thickness of the common carotid artery (CCA) and of its bifurcation (BIF) in 40 patients with essential hypertension, 20 of them with left ventricular hypertrophy (LVH; age 42 +/- 10 years) and 20 without LVH (age 44 +/- 12 years); no other major cardiovascular risk factor was present in all the patients. Both carotid axes have been scanned from different views (anterior, lateral, posterior) on a transversal and longitudinal section using a high-resolution steerable linear array of 5.0 MHz. Carotid diameter and thickness were measured in the longitudinal section. CCA parameters were assessed 20 mm caudally to the flow divider. In patients with LVH, blood pressure (172 +/- 21/108 +/- 9 mm Hg) and left ventricular mass index (156 +/- 38 g/m2) were significantly (p < 0.01) higher than in patients without LVH (blood pressure: 158 +/- 11/99 +/- 12 mm Hg; left ventricular mass index: 98 +/- 10 g/m2), while there was no difference in serum glycemia, triglycerides, total and fractioned cholesterol levels. The intima-media thickness of both the CCA and BIF was significantly higher in the hypertensives with LVH (CCA: 0.85 +/- 0.02 vs. 0.65 +/- 0.02 mm; BIF: 0.93 +/- 0.04 vs. 0.70 +/- 0.03 mm, p < 0.01). There was a statistically significant correlation between the carotid wall thickness and the left ventricular mass index.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of acute and chronic administration of verapamil on the anatomy and function of the left ventricle in essential hypertensive patients ]

The aim of this study was to analyze the acute and chronic effects of oral verapamil on diastolic function indices, derived from Doppler echocardiography and left ventricular (LV) dimensions and mass, assessed by M-mode echocardiography, in hypertensive patients (pts). Twelve essential hypertensive pts without LV hypertrophy were studied in basal conditions and 1) after a single oral administration of verapamil 160 mg and placebo, in double blind protocol and 2) over chronic treatment (six months) of verapamil 240 mg/day. At baseline the ratio between early and atrial-induced transmitral velocities (E/A ratio) was lower in pts than in 12 age-matched normal subjects (1.0 +/- 0.3 vs 1.5 +/- 0.3, p less than 0.01). Acute verapamil administration significantly decreased arterial blood pressure (162 +/- 26/101 +/- 15 to 142 +/- 12/88 +/- 7 mmHg, p less than 0.01) after two hours and increased the E/A ratio to 1.26 +/- 0.3 (p less than 0.05) after three hours. No change in ventricular dimensions or heart rate was observed. After chronic therapy we found a further increase in the E/A ratio (1.49 +/- 0.3, p less than 0.01) in 10 responder pts. The LV mass index, which was higher than in normal subjects before the treatment (118 +/- 16 vs 91 +/- 11 g/m2, p less than 0.01), was significantly reduced (100 +/- 17 g/m2, p less than 0.05 vs basal, ns vs normal subjects). Our results demonstrate that acute administration of verapamil only partially improves the abnormal indices of diastolic function in hypertensive pts, whereas chronic treatment, by reducing left ventricular mass indices and blood pressure to normal values, can completely normalize the indices of LV diastolic filling.

Effects of long-term blood pressure control on left and right ventricular structure and function in hypertensive patients

The functional and anatomical abnormalities of the right ventricle may occur in hypertensive patients with left ventricular hypertrophy (LVH). The present study was designed to assess the functional and structural changes in both left and right ventricles induced by chronic antihypertensive therapy. Doppler and standard echocardiography were performed in 10 hypertensive patients with LVH before and after 1 year of treatment with captopril alone (5 patients) or captopril plus nifedipine (5 patients). We found that the left ventricular mass index and right ventricular thickness were significantly reduced in all patients when compared with pretreatment values. Furthermore, the Doppler-derived diastolic filling indexes show a significant improvement of both ventricular chambers. Our data suggest that anatomical and functional changes induced by therapy in hypertensive patients are not limited to the left ventricle but also involve the right ventricle.

Left ventricular diastolic function in athletes and borderline hypertensives with mild cardiac hypertrophy

The aim of this study was to evaluate the diastolic function in athletes and in young borderline hypertensives with mild left ventricular hypertrophy. Left ventricular filling was assessed by echo Doppler measurement of transmitral flow velocity in 18 soccer players (age 22 +/- 4 years, left ventricular mass index, LVMI 136 +/- 12 g/m2), in 15 borderline hypertensives (age 21 +/- 3 years, LVMI 137 +/- 9 g/m2), and 20 normotensive subjects (age 22 +/- 4 years, LVMI 93 +/- 10 g/m2) as reference group. We found that left ventricular filling profile was similar in borderline hypertensives, in athletes and in normotensive subjects. These findings suggest that, at least in the early stage, mild cardiac hypertrophy secondary to borderline blood pressure elevation is characterized by indexes of diastolic function not different from those found in athletes with physiological hypertrophy.

Cardiac structure and function before and after acute and chronic verapamil administration in hypertensive patients

The aim of this study has been to analyze the acute and chronic effects of oral verapamil on diastolic function indices, derived from Doppler echocardiography, and left-ventricular (LV) dimensions and mass, assessed by M-mode echocardiography, in hypertensive patients without LV hypertrophy. 12 patients with essential hypertension were studied in basal conditions and (1) after a single oral administration of verapamil 160 mg and placebo in a double-blind protocol and (2) over chronic treatment (12 months) with verapamil 240 mg/day. At baseline, the ratio between early and atrial-induced transmitral velocities (E/A ratio) was lower in patients than in 12 age-matched normal subjects (1.08 +/- 0.2 vs. 1.51 +/- 0.3, p less than 0.01). Acute verapamil administration significantly decreased arterial blood pressure (162 +/- 26/101 +/- 8 to 142 +/- 12/88 +/- 7 mm Hg, p less than 0.01 after 2 h) and increased the E/A ratio to 1.26 +/- 0.3 (p less than 0.05) after 3 h. No change in ventricular dimensions and heart rate was observed. After chronic therapy, we found a further increase in the E/A ratio in 10 responder patients (1.49 +/- 0.3, p less than 0.01). The LV mass index, that was higher than in normal subjects before the treatment (118 +/- 16 vs. 91 +/- 11 g/m2, p less than 0.01), was significantly reduced (100 +/- 17 g/m2, p less than 0.05 vs. basal, nonsignificant vs. normal subjects). Our results demonstrate that acute administration of verapamil only partially improves the abnormal indices of diastolic function in hypertensive patients, whereas chronic treatment, by reducing LV mass indices and blood pressure to normal values, can completely normalize the indices of LV diastolic filling.

[Morphofunctional characteristics of the left ventricle in arterial hypertension: echocardiographic and Doppler study]

The role of arterial hypertension in the development of left ventricular hypertrophy is well documented; in contrast, the characteristics of the right ventricle in this condition are poorly defined. To investigate whether structural and functional changes of the right ventricle are associated with systemic hypertension, we studied a total of 105 patients using M-mode, 2D and pulsed-Doppler echocardiography. Of these, 31 were hypertensive patients with left ventricular hypertrophy (III), 42 were hypertensives without left ventricular hypertrophy (II) and 32 were normotensive controls (I). Right ventricular anterior wall thickness was measured from the parasternal window, in long axis. The following left and right ventricular filling parameters were evaluated using Doppler mitral and tricuspid flow analysis: the early (E) and late (A) peak velocity, the ratio E/A. Our results show that: right ventricular anterior thickness was 5.7 +/- 0.9 mm in III, 4.3 +/- 0.8 in II and 3.7 +/- 0.8 in I (p less than 0.05 II vs I, p less than 0.01 III vs II and I). There is a significant correlation between right and left ventricular wall thickness in the hypertensive population (r = 0.75, p less than 0.01). Left ventricular filling shows a progressive reduction in E and an increase in A with a progressive reduction in the E/A ratio from 1.47 in I to 1.31 in II and 0.78 in III. Similarly E/A ratio for right ventricular filling decreases from 1.70 in I, 1.32 in II and 0.92 in III.(ABSTRACT TRUNCATED AT 250 WORDS)

Right ventricular wall thickness and function in hypertensive patients with and without left ventricular hypertrophy: echo-Doppler study

The structure and function of the right ventricle in arterial hypertension have been the subject of only a few reports. The present study evaluated the functional and structural changes in both left and right ventricles. Doppler and standard echocardiography were performed in 58 hypertensive patients (33 without and 25 with left ventricular hypertrophy). We concluded that right ventricular wall thickness is significantly increased in hypertensive patients compared with normotensive subjects, and that there is a significant, direct correlation between right and left ventricular thickness. Abnormalities in right and left ventricular filling, characterized by a reduction in early and an increase in late diastolic flow velocity, occur in hypertensive patients, and there is a direct correlation between late mitral and tricuspidal flow velocities and left and right ventricular thickness.

Nadolol prevents the exercise-induced rise in lymphocyte beta-receptor number in borderline hypertension

Thirteen borderline hypertensives were investigated at rest and during dynamic exercise, before and after therapy with nadolol (40-80 mg/day for 7-28 days), in order to evaluate regulation of the number of lymphocyte beta-receptors. Systolic blood pressure and the heart rate were measured before and after 15 min of bicycle exercise, both with and without nadolol therapy; blood samples were withdrawn for adrenaline, noradrenaline and lymphocyte beta-receptor determinations. Nadolol induced a significant decrease in systolic blood pressure and the heart rate at rest, while plasma catecholamines and lymphocyte beta-receptors did not change significantly. Of the physiological responses to dynamic exercise (increases in systolic blood pressure, heart rate, plasma noradrenaline levels and adrenaline and lymphocyte beta-receptors), only the rise in beta-receptors was entirely prevented, and the increase in the heart rate was significantly attenuated by nadolol. It is suggested that the lack of a rise in the number of beta-receptors during exercise may contribute to the blunted exercise-induced tachycardia in patients taking nadolol.

Reciprocal changes in atrial natriuretic factor and aldosterone during angiotensin converting enzyme inhibition in man

To investigate whether aldosterone responses to angiotensin converting enzyme (ACE) inhibition are affected by changes in atrial natriuretic factor, which is known to inhibit aldosterone secretion, we measured blood pressure, plasma renin activity, aldosterone, atrial natriuretic factor and plasma potassium before and after 1 week of treatment with fosenopril, a long-acting ACE inhibitor, in eight normotensive subjects. Fosenopril caused a slight fall in blood pressure and increased plasma renin activity in all subjects. In contrast, aldosterone and atrial natriuretic factor were, on average, unchanged. However, for both these hormones a wide range of individual responses was observed (aldosterone from -254 to +240 pmol/l, atrial natriuretic factor from +9.7 to -16.6 pmol/l) and a significant inverse correlation was found between the changes in aldosterone and those in atrial natriuretic factor (r = -0.73, P less than 0.05). Plasma potassium was unchanged after the fosenopril treatment. These findings suggest an inter-relationship between atrial natriuretic factor and the aldosterone responses to short-term treatment with an ACE inhibitor.

Advantages and limitations of diuretic therapy in essential hypertension

The diuretics previously considered the "cornerstone" of the antihypertensive treatment have recently undergone a reevaluation and have been considered as a potential cause of the lack of "cardioprotection" found in different epidemiological studies. The reduction in plasma potassium and the changes in lipoproteins should represent the mechanisms of the negative interference of diuretics at cardiac levels. In spite of this common opinion, there is no clinically consistent evidence that the lowering of serum potassium and the changes in lipoproteins are responsible for the lack of cardioprotection during antihypertensive therapy. It is possible that other causes, for instance the reflex activation of sympathetic nervous system and/or renin secretion, may play an important role in determining the cardiac effects of antihypertensive therapy. However, it is also true that diuretics have been used in the past at doses that were too high, and the changes in serum potassium and lipoproteins can be minimized by administering lower doses of diuretics without decreasing their antihypertensive efficacy.

Nifedipine does not blunt the aldosterone and cardiovascular response to angiotensin II and potassium infusion in hypertensive patients

The antihypertensive response of calcium antagonists of the dihydropyridine series, although accompanied by a significant increase in plasma renin activity (PRA), is generally not associated with a comparably significant rise in plasma aldosterone (PA). This has been suggested to be due to the adrenal glomerular cell responsiveness being dependent on calcium entry. To investigate this hypothesis, angiotensin II (AII; 0.15, 0.375, and 0.750 micrograms/min, each step for 20 min) and KCl (30 mmol/50 min) were infused on separate days in 11 hypertensive patients kept at a constant daily intake of 100 mmol sodium and 40 mmol potassium, before and after 1 week of nifedipine treatment (20 mg b.i.d.). Supine blood pressure (BP) was significantly (p less than 0.01-p less than 0.001) reduced after nifedipine treatment; supine PRA increased significantly (p less than 0.01), while PA did not change significantly. No change in plasma potassium level was seen during nifedipine treatment. The dose-dependent mean BP rises induced by AII were slightly blunted during nifedipine treatment, whereas the PRA decreases and the PA rises after the peak infusion were not significantly different before and during nifedipine administration. Potassium infusion had no significant effect on BP, and caused a significant and similar rise in PA before and during nifedipine administration, while PRA decrease was more pronounced after nifedipine treatment. As previously shown in normotensive subjects, and also in hypertensive patients, aldosterone responses to two major stimulants, such as AII and potassium, do not appear to be blunted by treatment with a calcium antagonist.