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Biomedical subjects

U Manzoli

Publications and source records attributed to U Manzoli.

At least 37 records · Page 2Linked to original sources
PubMed1987

Circadian rhythm of ventricular tachycardia.

A 24-hr electrocardiographic monitoring was performed in 406 patients (297 with ischemic heart disease). Forty-one episodes of ventricular tachycardia were detected in 32 subjects (7.88%). The average rate of tachycardia was 127.4 (range 180-65). No correlation was observed between the rate of ventricular tachycardia and the heart rate 30, 20, and 10 min before and at the moment of the episode. A circadian rhythm of all the episodes was demonstrated, with an acrophase at 1102 hr. A different acrophase was observed for the QT interval. No significant rhythm was observed for premature ventricular beats in the patients with ventricular tachycardia. The circadian variation of tachycardia suggests that this arrhythmia is related to sympathetic tone, but it will require further studies with a larger number of patients with ventricular tachycardia to clarify this problem.

Circadian Rhythm↗
PubMed1986

Pulsed Doppler echocardiographic analysis of mitral regurgitation after myocardial infarction.

In 72 patients with previous myocardial infarction (MI), mitral regurgitation (MR) was assessed by pulsed-wave Doppler echocardiography and compared with physical and 2-dimensional echocardiographic findings. MR was found by Doppler in 29 of 42 patients (62%) with anterior MI, 11 of 30 (37%) with inferior MI (p less than 0.01) and in none of 20 normal control subjects. MR was more frequent in patients who underwent Doppler study 3 months after MI than in those who underwent Doppler at discharge (anterior MI = 83% vs 50%, p less than 0.01; inferior MI = 47% vs 27%, p = not significant). Of 15 patients who underwent Doppler studies both times, 3 (all with anterior MI) had MR only on the second study. Of the patients with Doppler MR, 12 of 27 (44%) with a left ventricular (LV) ejection fraction (EF) greater than 30% and 1 of 13 (8%) with an EF of 30% or less (p less than 0.01) had an MR systolic murmur. Mitral prolapse or eversion and papillary muscle fibrosis were infrequent in MI patients, whether or not Doppler MR was present. The degree of Doppler MR correlated with EF (r = -0.61), LV systolic volume (r = 0.47), and systolic and diastolic mitral anulus circumference (r = 0.52 and 0.51, respectively). Doppler MR was present in 24 of 28 patients (86%) with an EF of 40% or less and in 16 of 44 (36%) with EF more than 40% (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Assessment of left ventricular hypertrophy by ECG and VCG in patients with inferior and posterior myocardial infarction. A comparison with echocardiographic data.

Electrocardiographic (ECG) and vectorcardiographic (VCG) QRS voltage criteria have been analyzed in 26 patients with inferior and 17 with posterior myocardial infarction (MI) in comparison with left ventricular (LV) mass and global and regional wall motion as assessed by M-mode and two-dimensional (2D) echocardiography. Transverse plane QRS maximal vector correlated significantly with LV mass in patients with both inferior and posterior MI (r = 0.65 and 0.87, respectively, p less than 0.01). A transverse plane QRS maximal vector greater than 1.5 mV correctly recognized 12 of 15 (80%) and 9 of 12 (75%) patients with respectively inferior and posterior MI and LV mass greater than 221 gm. Of the ECG measurements, S V1-2 + R V5-6 correlated moderately with LV mass in patients with inferior MI (r = 0.47), and R V1-2 + R V5-6 correlated moderately with LV mass in those with posterior MI (r = 0.67). ECG and VCG QRS voltage data did not correlate with global and regional LV function as assessed by M-mode and 2D echocardiography. We conclude that: ECG and VCG QRS voltage parameters can be utilized for assessing non-invasively LV enlargement in patients with postero-inferior MI; ECG and VCG QRS voltage parameters should be utilized with caution for analyzing LV function or MI size in postero-inferior MI.

Adult↗
PubMed1986

Ventricular parasystole: a chronobiologic study.

Previous works have reported circadian rhythms for several cardiovascular parameters. A chronobiologic rhythm is characterized by: mesor (a rhythm-determined average), amplitude (half difference between the highest and lowest values), and acrophase (timing of high point in degrees and/or in hours) along with 95% confidence limits. We performed 24-hour ECG Holter monitoring in seven patients (mean age, 50.6 years) with ventricular parasystole (VP) in order to determine whether the chronotropic activity of parasystolic foci has a circadian rhythm similar to that of the sinus node. For each Holter recording parasystolic rates (PRs) and heart rates (HRs) were calculated every hour. Furthermore, a mean hourly PR and a mean hourly HR were calculated from the hourly PRs and HRs of the patients. The statistic chronobiologic analysis was done by single and mean cosinor methods. Correlation between mean hourly PR and HR was evaluated by Pearson's 'r' coefficient. A statistically significant rhythm (P less than 0.05) was found for the single and mean rhythms both of HR and PR. In our patients, HR had acrophase at 1.27 P.M., mesor at 73.28 beats/min, and amplitude at 9.53 beats/min, whereas PR had acrophase at 1.42 P.M., mesor at 38.31 beats/min, and amplitude at 3.64 beats/min. Chronobiological data and the high direct correlation between mean hourly HRs and mean hourly PRs (r = 0.96, P less than 0.001) indicate a similar circadian variability of the chronotropic activity of sinus nodes and parasystolic foci. Although several hypotheses can be made, responsiveness of parasystolic foci to circadian variations of the autonomic nervous system tone (sympathetic and/or vagal) and/or circulating substances (particularly catecholamines) seems the more probable one for explaining our findings.

Adolescent↗
PubMed1985

Ventricular arrhythmia induced by programmed ventricular stimulation after acute myocardial infarction.

The prevalence, characteristics and clinical significance of ventricular electrical instability with programmed ventricular stimulation was studied in 50 hemodynamically stable patients 17 to 40 days after acute myocardial infarction (AMI) using double extrastimuli at 2- and 10-mA intensity and from 2 right ventricular sites. Ventricular electrical instability was defined as induction of 10 or more consecutive intraventricular reentrant beats. Of 50 patients, 23 (46%) had ventricular electrical instability (10 of these had sustained ventricular tachycardia [VT] induced). No significant differences were observed between patients with and without ventricular electrical instability with respect to age, site of AMI, coronary prognostic index, maximal level of CK, number of narrowed coronary arteries and presence of severe wall motion abnormalities. During a mean follow-up of 11.2 months no patient died suddenly. During repeated Holter recordings patients with ventricular electrical instability had a higher incidence of nonsustained VT than did patients without ventricular electrical instability.

Adult↗
PubMed1985

Effects of L-carnitine on exercise tolerance in chronic stable angina: a multicenter, double-blind, randomized, placebo controlled crossover study.

L-carnitine was studied in forty-four men with stable chronic angina in a multicenter, double-blind, randomized, placebo controlled crossover trial. A cycloergometer exercise test was performed after a 10-day wash-out with placebo and at the end of each 4-week treatment period with either L-carnitine (1 g twice daily) or placebo. The mean (+/- SD) exercise work load showed an increase after L-carnitine compared to placebo (102.73 +/- 22.23 and 97.05 +/- 22.77 watts respectively, p = 0.001), as did the watts to onset of angina (95.7 +/- 24.07 and 87.44 +/- 24.67, p = 0.000). On the contrary, the ST segment depression was reduced by L-carnitine compared to placebo both at the maximum work load (1.40 +/- 0.90 and 1.69 +/- 0.82 mm, p = 0.05) and at the maximum work load common to L-carnitine and placebo (1.24 +/- 0.90 and 1.66 +/- 0.79 mm, p = 0.005). 22.7% of the patients became free of angina with L-carnitine and 9.1% with placebo. Resting and exercise blood pressure, heart-rate and double product were unaffected by L-carnitine. 1 patient decided to discontinue the trial because of gastric pyrosis while taking the active drug. The results of this study show that treatment with L-carnitine increases exercise tolerance and reduces ECG indices of ischemia in stable effort-induced angina.

Angina Pectoris↗
PubMed1984

Assessment of tricuspid regurgitation by pulsed Doppler ultrasonography of the hepatic veins.

Pulsed Doppler echocardiography was tested to assess the degree of tricuspid regurgitation (TR), classified by right ventriculography, in 47 patients. Forty-eight subjects without TR served as controls (39 with sinus rhythm and 9 with atrial fibrillation). Two Doppler methods were used: the distance of systolic turbulence within right atrium from the tricuspid plane and the quantitative analysis of the flow-velocity traces from the hepatic veins (HVs). Right atrial systolic turbulence was found in 41 of 47 patients with TR and in none of the control subjects, and moderately correlated with the angiographic grading (r = 0.57). In control subjects, TR flow-velocity traces from the HVs showed 2 anterograde flow waves, systolic and diastolic. The ratio of anterograde systolic/anterograde diastolic velocity was more than 0.6 in 38 subjects with sinus rhythm and in 8 with atrial fibrillation. Twenty-two control subjects had a positive wave (designated as "v") coincident with the end of T wave. In 30 patients with TR, a retrograde holosystolic wave was present. Of the remaining patients, 12 had a ratio of anterograde systolic/anterograde diastolic velocity less than 0.6. Fifteen had an end-systolic "v-like" wave, which occurred earlier than the v wave in control subjects (p less than 0.001). In patients with TR, maximal velocities of the anterograde diastolic and retrograde systolic flow correlated with angiographic grading (r = 0.74 and 0.73, respectively). An anterograde diastolic flow velocity more than 26 cm/s and a retrograde systolic flow velocity more than 16 cm/s excluded mild TR. Analysis of Doppler recordings of the HVs is valuable to semiquantitatively assess TR, complementing the right atrial Doppler findings.

Adolescent↗