R. Del Bene

Altered cardiovascular responsiveness to active tilting in nonalcoholic cirrhosis

BACKGROUND & AIMS The hyperdynamic circulation of cirrhosis has been related either to plasma volume expansion (increased preload) or peripheral arterial vasodilation (reduced afterload). The aim of this study was to evaluate cardiovascular function in patients with nonalcoholic cirrhosis by echocardiography. METHODS Nineteen patients with abnormal sodium handling (11 sodium excretors and 8 sodium retainers) and 15 healthy volunteers underwent echocardiographic evaluation of left ventricular end-diastolic volume index (LVEDVI) and left ventricular end-systolic volume index (LVESVI), left ventricular ejection fraction (LVEF), cardiac index (CI), mean arterial pressure, and systemic vascular resistance (SVR) during supine resting and after 5 minutes of standing. RESULTS Supine patients had increased LVEF and CI and reduced LVESVI and SVR. LVEDVI was increased only in sodium excretors. Standing induced a decrease in LVEDVI in all subjects. Healthy volunteers maintained cardiovascular homeostasis by increasing LVEF and heart rate, whereas cirrhotic patients experienced a decrease in SVI and CI despite marked increments in heart rate, plasma renin activity, and plasma norepinephrine level. CONCLUSIONS In patients with cirrhosis, the increased LVEF and reduced LVESVI while in a supine position point at reduced afterload as an important determinant of the hyperdynamic circulation. Evidence of an increased preload secondary to increased blood volume, indicated by a high LVEDVI and increased plasma atrial natriuretic peptide levels, was found only in sodium excretors. The altered response to active tilt in cirrhotic patients suggests an impaired myocardial contractility.

Post-ejection thickening as a marker of viable myocardium an echocardiographic study in patients with chronic coronary artery disease

Summary The study aim was to assess whether post-ejection thickening (PT) is an useful marker of viable myocardium in patients with chronic coronary artery disease.Twenty-three patients with critical coronary stenoses were submitted to dobutamine and dipyridamole stress-echocardiographies and dipyridamole-early-redistribution 201TI SPECT within 15 days from coronary arteriography. They were selected for the presence of PT in segments that could be optimally studied by M-mode echocardiography and were hypo-akinetic in basal conditons.PT (occurring between end-ejection and mitral valve opening) was found in 58% of dysfunctional critically perfused regions. Ninety-eight percent of the regions with PT and 6% of those without PT improved during low-dose dobutamine stress-echocardiography. Segments with PT had, respectively, higher and lower SPECT early-redistribution thallium activity than dysfunctional segments without PT and normokinetic regions. Therefore, regions with PT were viable and had a moderate decrease in coronary perfusion. Akinetic segments without PT did not show any inotropic reserve. After revascularization almost all the segments with PT improved.In conclusion, PT is a pattern of myocardial contraction easily detected by M-mode echocardiography in the clinical setting. If the results of this study are further confirmed, PT may become a sign for the recognition of myocardial viability.

Parallel increase in carotid, brachial and left ventricular cross-sectional areas in arterial hypertension

Few data have been published about the relation between the vessels geometry and development of left ventricular (LV) hypertrophy in patients with arterial hypertension. The aim of this study is to describe arterial and LV geometry changes due to mild-to-moderate arterial hypertension in an untreated hypertensive population. In 95 untreated patients with mild-to-moderate hypertension and 23 age- and sex-matched healthy normotensives, we measured the end-diastolic diameter and wall thickness of the left ventricle and the internal diameter and intimal-medial thickness (IMT) of carotid and brachial arteries. From these data, the cross-sectional areas (CSAs) of arterial and myocardial walls were calculated. Hypertensive patients were further subdivided on the basis of the presence of LV hypertrophy defined according to Devereux et al as anatomical LV mass >125 g/m. In hypertensive patients with hypertrophy, carotid and brachial CSAs increased, without significant changes in thickness/diameter ratio (arterial ‘enlargement’), while the left ventricle developed ‘concentric’ hypertrophy. Arterial and LV CSAs showed a significant direct correlation with systolic blood pressure (BP). However, when data were corrected for BP, the correlation between the increase in arterial and LV CSAs became much improved than for the raw data. In conclusion patients with untreated mild-to-moderate hypertension, both carotid and brachial arterial walls showed an enlargement that was proportional to the development of LV hypertrophy. These results suggest that the effects of arterial hypertension on carotid, brachial and LV wall geometry have a common modulation.

Cardiac autonomic modulation and incidence of late potentials in essential hypertension : role of age, sex, ventricular mass and remodeling

The influence of age, sex, left ventricular hypertrophy (LVH) and geometry on the autonomic activity to the heart was investigated in 96 hypertensive out-patients (53 men, mean age 53 ± 9 years) and 39 healthy subjects (19 men, mean age 43 ± 1 years). Using 24-h Holter recordings, time [the standard deviation of all RR intervals (SDNN) and the square root of the mean of the squared differences between adjacent normal RR intervals (RMSSD)] and power spectral analysis of RR intervals [Fast Fourier algorithm, low/high frequency (LF/HF) ratio] were calculated over 24 h, daytime (D) and night-time (N) periods in all subjects. Signal averaged electro-cardiogram was recorded in 50 patients to detect late potentials. Stepwise multiple linear regression analysis showed that the 24-h LF/HF ratio was influenced by age and sex, D-LF/HF by age and N-LF/HF by sex, a higher LF/HF ratio being found in younger patients and in men. These data suggest a more prominent sympathetic modulation of cardiac activity in these groups. No differences in RR period variations were observed between patients with or without LVH. Late potentials were observed in 10 patients, and did not correlate with any of the measured parameters.

Left ventricular shape reconstruction and description in 3D with application to self-referring echocardiographic reports

In order to improve the evaluation of echocardiographic stress tests, 3D reconstruction of left ventricular (LV) endocardial surface with a complete description of the shape and its modifications was obtained using a limited number (4-6) of long-axis apical views. Regularization theory was exploited in order to minimize an energy functional, i.e. the weighted sum of fitting mean square error and thin-plate surface variation. According to the finite element method, energy minimization was accomplished iteratively by means of the conjugate gradient descent algorithm and considering either a cylindrical parametrization or a spherical one. Koenderinks index was computed to map the endocardial surface onto a matrix of compact and invariant shape descriptors. Grouping and matching of hyperbolic and elliptical patches allowed regional deformation due to acute ischemia to be identified, whereas little variation was found in normal subjects.

Vascular reserve in the lower limbs of cirrhotic patients: a duplex Doppler ultrasound study

AIM To evaluate femoral artery impedance at rest and during reactive hyperaemia. PATIENTS Study population comprised 11 cirrhotic patients without ascites, 10 with ascites and 16 age- and sex-matched healthy subjects. METHODS Echocardiographic assessment of systemic haemodynamics; duplex Doppler ultrasound measurement of femoral artery pulsatility index and vascular reserve [pulsatility index rest/pulsatility index hyperaemia). RESULTS Cirrhotic patients had elevated cardiac index and low systemic vascular resistance. Pulsatility index (right femoral artery) was not statistically different either at rest or after reactive hyperaemia (controls: rest 10.6 +/- 0.4, hyperaemia 2.6 +/- 0.2; compensated cirrhosis: rest 10.1 +/- 0.8, hyperaemia 3.4 +/- 0.4; ascitic cirrhosis: rest 11.4 +/- 1.6, hyperaemia 2.9 +/- 0.4. Vascular reserve was 4.38 +/- 0.35 in controls, 3.33 +/- 0.39 in compensated and 4.70 +/- 0.89 in ascitic cirrhosis (p = not significant). No correlation was found between systemic haemodynamic parameters and either pulsatility index or vascular reserve. CONCLUSIONS The lower limb vascular reserve is preserved in cirrhosis.

Left ventricular wall stress and thickness from 3D echocardiography in hypertensive patients

The authors applied a previously described method for 3D LV reconstruction from a limited number of long-axis 2D echocardiographic images to obtain epicardial and endocardial surfaces. By intersecting a regularly-spaced set of lines perpendicular to the center-surface with the endocardial and epicardial surfaces, LV local thickness was measured. Accuracy was improved by considering cubic spline patches rather than planar ones. LV volumes, mass and Janzs stress index were computed. The goal of this work was to quantitatively evaluate the degree of LV hypertrophy, its spatial distribution in 21 patients with hypertension and to compare them to the standard M-mode mass values. Results indicate a good correlation between conventional echocardiographic and 3D estimated mass. Different patterns in the spatial distribution of myocardial hypertrophy were responsible for a scattering of data.