[Contractility and left ventricular filling in heart failure: an echocardiographic evaluation]. / La contrattilità e il riempimento del ventricolo sinistro nell'insufficienza cardiaca: valutazione ecocardiografica.

In this paper we analyze the possibility of investigating the various modalities of pump function alteration by the echocardiographic technique through examination of the different parts of the cardiac cycle. While M-Mode and 2D echocardiography make a precise assessment of the systolic function parameters possible, with the Echo-Doppler technique we can study diastolic function and obtain information about many hemodynamic parameters. "Strain dependent" and "strain independent" diastolic function are studied almost exclusively with the Echo-Doppler technique: the diagnosis of restrictive cardiomyopathy can be established without invasive procedures such as cardiac catheterization. We suggest that, in most heart diseases with cardiac failure, diastolic and systolic dysfunction coexist: in mitral and aortic regurgitation, echocardiography can give precise information on the presence of ventricular dysfunction, even in the presence of very few or no symptoms, which helps the cardiologist make an early surgical or non surgical decision when dealing with such valve pathologies.

Lack of correlation between transient myocardial ischemia and late potentials on the signal-averaged electrocardiogram.

The relation between transient myocardial ischemia and late potentials was investigated in 100 patients with coronary artery disease who underwent serial recordings of the signal-averaged electrocardiogram before, during and after dipyridamole infusion. During this test, 47 patients (group 1) developed transient myocardial ischemia (with ST elevation in 14 cases and ST depression in 33), whereas 53 patients (group 2) did not. Baseline signal-averaged electrocardiogram was abnormal in 20 patients (20%): a QRS duration greater than 115 ms was seen in 6 patients, a late potential (root mean square voltage of last 40 ms of QRS [RMS40] less than 25 microV) in 9, both abnormalities in 5, with no significant differences between groups 1 and 2 (26 vs 15%, respectively). In both groups, comparison of recordings obtained before, during and after dipyridamole test revealed no significant changes in QRS duration and RMS40. Absence of significant differences was also observed when patients with transient ischemic ST elevation or ST depression were examined separately. During the test, 100% of abnormal basal recordings remained abnormal and 98% of normal recordings remained within normal limits. In only 2 patients (from group 1) RMS40, which showed borderline values at baseline, decreased to abnormal values during dipyridamole test. These data suggest that electrophysiologic abnormalities induced by transient myocardial ischemia may not bear any relation with the substrate for chronic reentrant ventricular tachyarrhythmias, as reflected by late potentials on the signal-averaged electrocardiogram.

Prevalence, time course and malignancy of ventricular arrhythmia during spontaneous ischemic ST-segment depression.

Ventricular arrhythmias during transient myocardial ischemia were studied in 60 patients with spontaneous angina and greater than or equal to 1 ischemic attack with ST-segment depression during 24-hour ambulatory electrocardiography. The patients were divided into 2 groups: group 1, 10 patients (17%) who developed ventricular arrhythmias during 26 of 92 (28%) ischemic attacks; and group 2, 50 patients who did not show this phenomenon. Daily ischemic attacks, total ischemic time and the proportion of symptomatic ischemic attacks were significantly greater (p less than 0.01) in group 1 versus group 2. In group 1 patients, ischemic attacks were found to have twice the duration in the presence of arrhythmias than in their absence (20.4 +/- 11.9 vs 9.1 +/- 8.4 minutes, p less than 0.01); arrhythmias were more common during symptomatic than during silent ischemic attacks (39 vs 13%, p less than 0.02). Arrhythmias occurred at the onset or peak of ST-segment depression (ischemia phase) in 6 cases (60%), during the resolution of ST-segment depression (recovery phase) in 2 cases (20%) and during both phases of ischemic attacks in the remaining 2 (20%). When compared to recovery phase arrhythmias, ischemia phase arrhythmias were characterized by a later onset time (173 +/- 144 vs 58 +/- 54 seconds, p less than 0.01) and a longer duration (105 +/- 107 vs 41 +/- 22 seconds, p less than 0.01). During the ischemia phase, 16 of 353 ventricular premature complexes initiated ventricular tachycardia, while during the recovery phase only 1 of 161 ventricular premature complexes resulted in ventricular tachycardia (4.5 vs 0.6%, p less than 0.02). Thus, ventricular arrhythmias may accompany spontaneous ischemic ST-segment depression, when the latter is recurrent, prolonged and symptomatic; arrhythmias are characterized by a greater frequency, duration and malignancy during the ischemia phase than during the recovery phase of ischemic attacks.

[Negative post-ischemic T waves in variant angina]. / La T negativa post-ischemica nell'angina variante.

The clinical and prognostic significance of negative T waves on the basal electrocardiograms of patients with unstable angina has been recently investigated with controversial results. Moreover, there is little data regarding this phenomenon in patients with variant angina. In order to evaluate the significance of negative post-ischemic T waves in patients with variant angina, 72 patients underwent Holter recording and coronary angiography. Negative T waves were present in 38 out of 72 patients (53%): they were anterior in 24 cases and inferior in 14 cases. The negative T-wave phenomenon was present in 29 patients on admission and showed up in 9 patients during hospitalization. Holter recording showed no significant differences between patients with or without negative T waves with regards to: 1) the proportion of symptomatic transient myocardial ischemic attacks; 2) the frequency of arrhythmias during transient myocardial ischemic attacks; 3) the maximum duration of transient myocardial ischemic attacks; 4) the maximum degree of ST elevation during transient myocardial ischemic attacks. Negative T waves on the anterior leads showed a moderate sensitivity (54%) and total predictive accuracy (52%), as well as a lower specificity (43%) and negative predictive accuracy (15%) for a significant stenosis of the left anterior descending coronary artery. This was due to the presence of several patients with left anterior descending artery stenosis and without negative T waves. On the other hand, negative T waves on the inferior leads were characterized by high sensitivity (85%), specificity (80%) and total predictive accuracy (82%) for a significant stenosis of the right coronary artery and/or the circumflex artery.(ABSTRACT TRUNCATED AT 250 WORDS)