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Attivazione neurormonale
No full textDescrive i principali sistemi neurormonali che vengono attivati in corso di insufficienza cardiac
Possible influence of hemodynamic and neurohormonal factors on the heart's response to arterial hypertension
No full textHypertrophy represents a frequent but inconstant response of the heart to hypertension and probably other nonhemodynamic factors are involved. We have performed 2D and Doppler echocardiography and assessed of neurohumoral pattern in 85 untreated patients with hypertension (diastolic blood pressure: 101 +/- 12.8 mmHg). Left ventricular hypertrophy was defined as a mass index greater than 134 g/m2 in males and 110 g/m2 in females. Doppler evaluation of left ventricular filling pattern was performed to detect the possible association of hypertrophy and diastolic dysfunction. In all patients the following neurohumoral substances were sampled and tested: plasmatic renin activity (PRA), aldosterone and norepinephrine. At Doppler echocardiography, 27 patients had hypertrophy and diastolic dysfunction, 15 only hypertrophy and 43 only diastolic dysfunction. The presence or absence of morpho-functional anomalies were independent of age, duration of hypertension and blood pressure levels. The mean value of neurohumoral substances were: norepinephrine 323.3 +/- 245 pg/ml, PRA 2.5 +/- 4 ng/ml/h, aldosterone 153.58 +/- 102 pg/ml. A significant correlation was found between PRA and blood pressure, and between aldosterone and all the Doppler-derived parameters of diastolic dysfunction. In conclusion, left ventricular hypertrophy seems to be related to alteration in ventricular geometry rather than to hemodynamic factors. Among nonhemodynamic factors, aldosterone may be the most responsible for abnormal filling, presumably through the activation of collagen matrix growt
Doppler echocardiographic evaluation of Right Ventricular Function in Patients with Right Ventricular Infarction
No full textThe aim of the present study was to assess the utility of the myocardial performance index in patients with right ventricular infarction. During the study period, 120 patients were evaluated: 50 patients had a right ventricular infarction and 70 patients had an inferior left ventricular infarction without right ventricularinvolvement. On admission, an echocardiogramwas obtained from all patients prior to the initiation of thrombolytic therapy. The right ventricular myocardial performance index was calculated, aswere the Doppler-derived parameters of the right side of the heart. All patients with right ventricular infarction had undergone a right ventricular dilation, compared with 70 patients with left ventricular infarction (right ventricular end diastolic diameter32 ± 13 versus 26 ± 24 mm; P < 0.01) and increased areas (diastolic area 24.8 ± 9.9 versus 15.1 ± 6.8 cm2;P < 0.01). Tricuspid regurgitation was detected in 26 patients. The mean peak velocity of tricuspid regurgitation was 3.8 ± 0.8 m/s. The Doppler intervals,isovolumetric contraction times (136 ± 30 versus 49 ± 11 ms; P < 0.01), and relaxation times (71 ± 28 versus 37 ± 9 ms; P < 0.01) were prolonged in patients with right ventricular infarction, whereas the ejection time was significantly reduced (250 ± 31 versus 330 ± 26 ms; P < 0.001). The myocardial performance index was significantly increased in patients with right ventricular infarction (0.85 ± 0.2 versus 0.26 ±0.1; P < 0.01). The inferior vena cava collapse was reduced in all patients with right ventricular infarction (35 ± 20%). The right ventricular myocardial performance index was a useful indicator of right ventricular performance in patients with right ventricularinfarction. The use of echocardiographic parameters of the right side of the heart and Doppler echocardiographic parameters of right ventricular function provides a reliable diagnosis of right ventricular infarction
Influence of pacing modalities on the incidence of atrial fibrillation in patients without prior atrial fibrillation: a prospective study.
No full text.....Aim. Many studies suggest that patients who receive a physiological pacemaker have a reduced incidence of atrial fibrillation compared to patients receiving a ventricular pacemaker. Methods. In order to evaluate the impact of different pacing modalities on the incidence of atrial fibrillation, we prospectively analysed 210 patients. Patients with previous episodes of atrial fibrillation were excluded from the study. The patient population included 110 patients paced for sick sinus syndrome and 100 patients paced for total atrioventricular block or second degree type atrioventricular block. Results. Patients were followed for 5 years; the incidence of atrial fibrillation was 10% at 1 year, 23% at 3 years and 31% at 5 years. There was an increase in the incidence of atrial fibrillation in patients receiving a ventricular pacemaker compared to patients receiving a physiological pacemaker. Conclusion. The pacing modality appeared to influence the incidence of atrial fibrillation in paced patients; patients with ventricular pacing had a significantly higher incidence of arrhythmias than did patients with physiological pacing
Relationship between mean right atrial pressure and Doppler parameters in patients with right ventricular infarction
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Left Atrial Anatomy and Function After Atrial Fibrillation of Brief Duration in Hypertrophic Hearts
No full textThe aim of the study was to evaluate the influence of left ventricular (LV) hypertrophy on left atrial (LA) electrical and mechanical function after cardioversion atrial fibrillation (A-Fib) ofbrief duration. Study group A included 100 patients with a first diagnosis of hypertension who had a moderate LV hypertrophy. The patient population included 64 men and 36 women with a mean age of 55 ±7 years who were hospitalized because of A-Fib and were cardioverted with external DC shock. Control group B included 100 patients without cardiac hypertrophy cardioverted because of lone A-Fib. Atrial function and size were assessed by Doppler echocardiography and the following parameters were measured: transmitral peak A velocity, atrial filling fraction, atrial ejection force, peak E velocity, deceleration time, and isovolumic relaxation time, LA maximal and minimal volume, and LV cardiac mass index. Baseline echocardiography showed that LA diameters and volumes were enlarged in all patients during A-Fib. After the restoration of sinus rhythm LA diameters and volumes decreased and the reduction was more evident in group B compared to group A. LA function as a continuous variable was negatively related to LV mass index (r = –0.77), LA diameter (r = –0.66 and r = –0.69 for the superoinferior diameter), LA maximal volume (r = –0.61) and LA minimal volume (r = –0.55) (all p <0.01).Atrial ejection force as a continuous variable was positively related to age (r = 0.78), peak A wave velocity (r = 0.71), systolic blood pressure (r = 0.51), and IVRT (r =0.41) (all p <0.01).Hypertrophy influenced the recovery of atrial function after cardioversion of A-Fib. Atrial function was reduced in patients with LV hypertrophy even after A-Fib of brief duration
Beta Blockers and the Big Heart in the treatment of heart failure
No full textAnalyzed the effects of many drugs in patients with dilated heart and heart failur
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