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Biomedical subjects

E Piccolo

Publications and source records attributed to E Piccolo.

At least 73 records · Page 4Linked to original sources
PubMed1984

[Value of a serial electropharmacologic study in survivors of a cardiac arrest secondary to ventricular tachycardia or ventricular fibrillation].

Electrophysiologic studies were performed in 10 patients (8 M, 2 F, mean age: 60.2 yrs) who had survived an episode of cardiac arrest due to ventricular tachycardia (VT) or ventricular fibrillation. The purpose was to evaluate the usefulness of serial acute drug testing in selecting an effective chronic antiarrhythmic regimen. The cardiac arrest had always been sudden and unexpected. It occurred outside the hospital in 7 cases and in the hospital in 3 cases. Patients in whom cardiac arrest was associated with evidence of acute myocardial infarction were excluded from the study. Nine of the patients were suffering from chronic ischemic heart disease with 1 or more previous myocardial infarctions while 1 had no evidence of organic heart disease. A ventricular aneurysm was present in 4 of them. During control electrophysiologic study a sustained VT was induced by ventricular stimulation (single and double extrastimuli at various paced ventricular cycle lengths + bursts of rapid ventricular pacing) in 9 of the 10 patients (90%) and a non sustained VT was induced in 1 of them (10%). In 3 patients (30%) VT could be initiated only by right ventricular stimulation at a site different from the apex (outflow tract). During serial acute drug testing a totally effective drug regimen (successful in preventing the induction of any ventricular arrhythmia) was found in 6 of the 9 patients (66.7%) who underwent this procedure and a partially effective drug regimen (sustained VT no longer inducible, easier to interrupt and considerably slower) was found in 2 patients (22.2%). None of the patients who received a chronic antiarrhythmic therapy based on the results of serial acute drug testing died suddenly during a mean follow-up of 14.8 months (range: 3-29) and only 1 had a recurrence of cardiac arrest. The latter, however, was taking antiarrhythmic drugs at a dosage less than that proved to be effective during electropharmacological testing. The only patient who refused serial acute drug testing and received an empiric antiarrhythmic therapy died suddenly at the 21st month of the follow-up. It is also noteworthy that amiodarone, alone or in combination, was given chronically to 6 of our patients (60%). These results 1) indicate that serial electropharmacological testing is useful in selecting an effective long-term drug regimen in survivors of cardiac arrest, and 2) suggest that amiodarone may be effective in preventing sudden death in these patients.

Adult↗
PubMed1984

Mid-diastolic intraventricular functional block. A new mechanism for intermittent intraventricular blocks?

Experimental and clinical studies have demonstrated the existence of phase 3 and phase 4 functional blocks. In this report six cases are presented in which the electrophysiological study demonstrated the existence of a functional intraventricular block different from phase 3 and phase 4 blocks. In these cases the occurrence of the block was related to the presence in mid-diastole of a zone of block preceded and followed by intervals of unimpaired conduction. In two of 6 cases the functional block (infrahisian block) was not present in the basal tracing; it occurred during programmed atrial stimulation in a range of critical H1H2 coupling intervals delivered late in diastole, and did not appear after earlier stimuli. In the remaining four cases the conduction disturbance (2 RBBB, 2 infrahisian blocks) was present in the basal tracing, but disappeared both during early and late supraventricular extrastimuli, the first having short H1H2 intervals, the latter having H1H2 intervals longer than H1H1 basal cycle length. The width of the mid-diastolic zone of block varied from a few msec to hundreds of sec, and increased as heart rate increased. Two hypotheses are put forward in order to explain the electrophysiological mechanism responsible for the phenomenon: 1) a longitudinal dissociation in the conducting system, generating two different ways, one having a long refractory period, the other having a phase 4 spontaneous depolarization; they would be responsible of phase 3 and phase 4 blocks respectively. The early and late zones of conduction could be explained by an alternate conduction in one of the two ways, while the mid-diastolic zone of block could be due to a simultaneous block in both ways; 2) the existence of a diastolic oscillatory potential (late after-depolarization). In the latter case we can suppose that the mid-diastolic block was due to the stimulation of the cells of the conducting system before the restoration of the normal diastolic potential. Our electrophysiological data offer a new contribution to the understanding of intermittent intraventricular blocks. However further experimental and clinical studies are needed to confirm our electrophysiological hypotheses.

Adult↗
PubMed1983

Possible role of a ventricular conduction disturbance in the electrogenesis of the ECG-VCG signs of myocardial infarction.

The typical QRS patterns of myocardial infarction (MI-QRS) are commonly attributed to myocardial cellular death. However, observation of a transient appearance of MI-QRS during coronary insufficiency, the disappearance of MI-QRS after coronary by-pass surgery and the appearance of MI-QRS after intracranial hemorrhage suggest that a different electrophysiological mechanism may be at work. There is a single convincing explanation for all these observations. It seems possible, at least theoretically, that a localized conduction disturbance can generate or contribute to the generation of the MI-QRS. The results obtained in nine out of 194 cases studied by means of premature right atrial stimulation (PRAS) in our laboratory seem to confirm this hypothesis. In five of them we observed typical MI-QRS in the aberrant beats which were absent in the basal tracings. In the other four cases, MI-QRS which were present in basal tracings disappeared in the aberrant beats. In three of these a reduction in the duration of QRS was also observed, while in the fourth the duration of QRS did not change. In no case could the alterations of QRS (induction or disappearance of MI-QRS) be explained by a classical conduction disturbance, preexcitation or by a premature ventricular beat. While the induction of MI-QRS was clearly due to an aberrant conduction in the supraventricular beats, the disappearance of basal MI-QRS changes in premature supraventricular beats is more difficult to explain. One possible electrophysiological mechanism could be a supernormal phase conduction. If this is the case, the basal MI-QRS could be due to a ventricular conduction disturbance. In conclusion, our results suggest that MI-QRS can be generated, at least in our cases, by a localized conduction disturbance.

Adult↗
PubMed1983

[Clinical and prognostic significance of hyperkinetic ventricular arrhythmias].

Ventricular arrhythmias, mainly ventricular premature beats (VPBs) are omnipresent in the general population. They may be detected or induced by means of different techniques such as routine ECG, ambulatory ECG-monitoring, exercise testing and ventricular stimulation during an intracavitary electrophysiologic study. The prevalence and clinical-prognostic significance of VPBs are highly related to the presence and severity of an underlying heart disease. Simple and complex (bigeminal, multiform, repetitive or R on T) VPBs are much more frequent in cardiac patients than in normal subjects. Acute myocardial infarction (AMI), chronic coronary heart disease (CCHD), cardiomyopathies and mitral valve prolapse are the most common clinical conditions in which VPBs occur. In apparently healthy persons, the presence of VPBs does not seem to indicate a greater risk for the future development of cardiac disease. In patients with AMI frequent, and complex VPBs often precede primary ventricular fibrillation and appear to be directly related to the size of the infarct. In the posthospital phase of AMI, as well as in CCHD, the occurrence of high-grade VPBs usually indicates more advanced degrees of both coronary and left ventricular disease as well as the possibility of cardiac and/or sudden death. In cardiomyopathies and mitral valve prolapse the VPBs do not correlate with either clinical, electrocardiographic, echocardiographic or hemodynamic parameters but their complex patterns appear to be a good indicator of patients with high sudden death risk.

Adolescent↗
PubMed1982

Effects of oral calcium-antagonists in spontaneous angina. Verapamil and nifedipine in a double-blind cross-over trial.

Verapamil and nifedipine, two calcium-antagonist drugs, were evaluated in a double-blind cross-over trial. The study was performed in 15 patients admitted to our Coronary Care Unit for spontaneous angina. Before and after a 24 hours placebo period, oral verapamil 480 mg daily and oral nifedipine 60 mg daily were administered alternatively. Symptomatic as well as asymptomatic ischemic episodes with ST segment elevation or depression and ventricular and supraventricular ectopic beats were documented by continuous electrocardiographic Holter monitoring. The average number of attacks during the placebo periods was 243; the number of attacks decreased to 129 during verapamil treatment (P less than 0.05) and to 57 during nifedipine treatment (P less than 0.01). Ventricular ectopic beats decreased with both drugs while supraventricular ectopic beats decreased only during verapamil treatment. The difference was not statistically significant because of a small number of observations. In conclusion the two drugs appear to be effective in the management of patients with unstable angina at rest, especially in the variant form.

Angina Pectoris↗
PubMed1982

[Clinical significance of corrected sinus node recovery time and natural and unnatural history of sinus node dysfunctions. A four-year prospective follow-up of 101 cases].

The clinical significance of corrected sinus node recovery time (CSNRT) and the natural and unnatural history of sinus node dysfunctions are not completely known. To gain some insight into this problem, 101 patients (pts) (54M, 47F, mean age +/- SD = 62.02 yrs +/- 14.42) with clinical and ECG signs of definite or suspected sick sinus syndrome (SSS) underwent an electrophysiologic study and then were prospectively followed for a mean period of 44.36 months +/- 18.96 (range: 2-78 months). The pts were divided into two groups: 1) Group A: 68 pts with prolonged CSNRT (greater than 500 msec); 2) Group B: 33 pts with normal CSNRT. Thirty-three pts of Group A (48.5%) and 2 pts of Group B (6.1%) received VVI pacemaker implantation (PM) immediately after the electrophysiologic study. The following results were obtained: 1) Pts of Group A showed a higher prevalence of organic heart disease and of ECG signs of definite SSS than pts of Group B. (p less than 0.05). Moreover, the higher the CSNRT in Group A pts, the more severe the ECG abnormalities of SSS. 2) Pts without PM, both of Group A and Group B, noted during the follow-up period a disappearance of neurological symptoms (syncopes and/or dizziness) and of ECG abnormalities of SSS in more than 50% of the cases. However, this was less evident in Group A pts compared with Group B pts (53.8% vs 78.6% regarding neurological symptoms and 54.3% vs 74.1% regarding ECG abnormalities of SSS) as well as in pts with organic heart disease in comparison with those with primitive SSS. Moreover, the number of pts who needed PM implantation during the follow-up period due to the worsening of clinical and ECG signs of SSS were higher in Group A than in Group B (20% vs 6.5%). The occurrence of cardiac death among the pts without PM was similar in pts of Group A (8.5%) and in those of Group B (9.7%). One pt of Group A without PM died suddenly (less than 1 hour). 3) Pts who required PM implantation were older (p less than 0.01) and showed a prevalence of organic heart disease higher (p less than 0.05) than those who did not require PM implantation. Pts with PM, both of Group A and Group B, showed a complete disappearance of syncopes and a clear-cut reduction of dizziness after implantation of it. On the contrary, dyspnea nearly always persisted and sometimes appeared when initially absent. Sudden and non-sudden cardiac death in PM pts (13.6%) was somewhat more frequent than in those without PM. 4) The incidence of stable atrial fibrillation was 12.1% in pts without PM and 27.2% in pts with PM. The occurrence of stable atrial fibrillation in pts without PM was generally not followed by clinical improvement. 5) The incidence of cerebrovascular accidents was approximately 8%. The accidents always occurred in pts with organic heart disease and often in the older pts (mean age: 75.1 yrs +/- 5.7) particularly in those with PM. A bradycardia-tachycardia syndrome was observed only in 3 pts who had a stroke...

Cardiac Pacing, Artificial↗
PubMed1981

["Left bundle branch block" pattern induced by premature right atrial stimulation. Electrogenetic and clinical considerations (author's transl)].

Although in the last years very important knowledges have been obtained in the field of the intraventricular conduction disturbances, many electrocardiographic-vectorcardiographic findings concerning the left bundle branch block (LBBB) and their electrogenesis are still controversial. With the purpose to clarify this problem we have reviewed and analysed 23 cases in whom BCG-VCG patterns of "complete" or "incomplete" LBBB were induced by the premature right atrial stimulation (PRAS) during an electrophysiologic study in man. The analysis of these cases have demonstrated that: 1) the same LBBB pattern can be caused by a slowed conduction or block at different sites of left intraventricular conduction system i.e. not only in the main stem of the left bundle branch (LBB) (tronkular LBBB) but also within the bundle of His (intra-His LBBB) or in all the three fascicles of the LBB distally to its subdivision (divisional LBBB); 2) ECG-VCG are not able to distinguish the anatomical or functional site of slowed conduction or block; 3) the right or left axis deviation in the LBBB is not due to LBBB per se but it represents or a block at two different sites, i.e. a tronkular or intra His LBBB plus a block in the anterior or posterior subdivision of the LBB, or a block at only one side i.e. a tronkular, intra-His or divisional LBBB but with prevalent involvement of one fascicle of the LBB; 4) the ECG-VCG "incomplete" LBBB pattern is similar to that of the left ventricular enlargement; 5) figures of "atypical LBBB" are not specific of myocardial necrosis; 6) the criteria for the diagnosis of "complete" LBBB are not reliable. We conclude that, since LBBB pattern does not always correspond to a slowed conduction or block in the main stem of the LBB, the current terminology of LBBB is inappropriate and could be changed with another which considers the site of delayed activation and not the site of slowed conduction. Therefore we propose the following terminology: 1) generalized left ventricular activation delay instead of LBBB without axis deviation; 2) generalized left ventricular activation delay superiorly predominant instead of LBBB with left axis deviation; 3) generalized left ventricular activation delay inferiorly predominant instead of LBBB with right axis deviation.

Adult↗
PubMed1981

[The right ventricular activation in ventricular activation delays. An endocardial mapping study (author's transl)].

To investigate the right ventricular activation, filtered bipolar recordings (1 cm interelectrode distance) of Apex (RVA), Inflow tract (RVIT) and Outflow tract (RVOT) of the right ventricle were obtained in 4 groups of subjects. 1st group: 25 cases with normal QRS; 2nd group: 7 cases with left ventricular conduction disturbances (4 LBBB and 3 LAH patterns); 3rd group: 20 cases with chronic coronary heart disease (CCHD) and RBBB alone (5 cases) or combined with LAH (15 cases); 4th group: 9 young subjects without heart disease (7 cases) or ostium secundum atrial septal defect (2 cases) and RBBB pattern. The activation times were calculated from the beginning of the QRS in the first endocavitary rapid deflection. The data obtained (average +/- s.d.) for QRS duration (QRSd), RVA, RVIT and RVOT were respectively: 1st group: 97 +/- 9, 23 +/- 9, 36 +/- 9, 39 +/- 8; 2nd group: 133 +/- 43, 20 +/- 14, 25 +/- 9, 42 +/- 6; 3rd group: 152 +/- 12, 49 +/- 13, 61 +/- 18, 82 +/- 20; 4th group: 130 +/- 17, 39 +/- 12, 58 +/- 12, 55 +/- 27. Activation times as expected were similar in 1st and 2nd groups. Significant differences were noted between 1st and 3rd groups (p less than 0.001) in activation times of RVA, RVIT and RVOT. Between 1st and 4th group significant differences were noted in activation times of RVA and RVIT (p less than 0.001) while no significant differences were observed for RVOT (p greater than 0.05). In 2 cases of the third group (CCHD) and in the 2 cases of atrial septal defect the activation time of RVA was within the normal range suggesting a peripheral block. In the cases of the 3rd group with troncular RBBB activation times of RVIT and RVOT were significantly related to the QRSd (r = 0.79 and 0.65, p less than 0.001 and less than 0.01 respectively), while there was no significant correlation between the activation time of RVA and the QRSd. In accordance with other Authors our study demonstrates that: 1) the RBBB pattern in ASD has a peripheral electrogenesis; 2) the RBBB pattern in CCHD is generally due to a troncular block but our study also suggests the possibility of a distal block in these patients. In contrast with some Authors the RBBB pattern in young people without heart disease was due to a troncular and not to a peripheral block. Finally, the absence of correlation observed in the cases with troncular block of the 3rd group: 152 +/- 12, 49 +/- 13, 61 +/- 18, 82 +/- 20; 4th group: 130 +/- 17, 39 +/- 12, 58 +/- 12, 55 +/- 27. QRSd and RVIT and RVOT activation times might be explained as follows: 1) in high degree troncular block the RVA activation time is due to the time employed byt the wave front to cross the septum which is probably similar in all the cases; 2) the QRSd depends on the activation time of the peripheral areas which depends on the variable spread of activation of the right ventricle probably due to a variable participation of the specialized conduction system.

Adolescent↗
PubMed1980

The anterior displacement of the QRS loop as a right ventricular conduction disturbance. Electrophysiologic and vectorcardiographic study in man.

Anterior displacement (AD) of the QRS horizontal loop (Frank VCG method) was induced by programmed right atrial stimulation (PRAS) in 15 cases. When AD occurred we noticed changes of the terminal QRS vectors and of the T loop similar to those observed in incomplete right bundle branch block (RBBB). The increasingly anticipated extrastimuli induced progressively the AD and then progressive degrees of RBBB. The anterior shifting of the efferent limb never appeared after the induction of RBBB. A left conduction disturbance never appeared after the AD. In cases of supposed incomplete left bundle branch block (i.e. left ventricular hypertrophy) the QRS duration decreased when the AD was induced. Therefore, the AD induced by PRAS and probably those observed in some clinical cases are due to a right ventricular conduction disturbance.

Adult↗
PubMed1980

[Prevalence of arterial hypertension in the community. Experience of the province of Veneto].

In the context of a W.H.O. Community Control Program of Hypertension, 15.187 subjects aged 20-64 years were examined in three distinct areas of the Veneto region: Camposampiero (Padua), Valdagno (Vicenza) and Mirano (Venice). The prevalence of hypertension was evaluated according to W.H.O. criteria. The prevalence of the three forms of hypertension "systolic only", "diastolic only" and "systo-diastolic together", the difference according to sex and the correlation with age were also calculated. In particular the correlation with age was evaluated in four arbitrary classes of relative weight. The mean prevalence of hypertension into the three samples was 30.7%. The most common form was "systo-diastolic together" (15.5%). The prevalence of hypertension was higher in males and increased with age in both sexes. A positive association between the prevalence of hypertension and the age was observed in all the three classes of relative weight. This association was more noticeable in the classes of a higher relative weight. The association between weight and prevalence of hypertension is discussed in view of a primary prevention of hypertension. The results obtained clearly show the extent of the effort involved in order to control hypertension in the community.

Adult↗