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Biomedical subjects

G Pinelli

Publications and source records attributed to G Pinelli.

At least 19 recordsLinked to original sources
PubMed1996

Transient sympathovagal imbalance triggers "ischemic" sudden death in patients undergoing electrocardiographic Holter monitoring.

OBJECTIVES: The aim of this study was to investigate the relation between "ischemic" sudden death (arrhythmic death preceded by ST segment shift) and autonomic nervous system activity. Background. Mechanisms precipitating sudden death are poorly known despite the importance of detecting functional factors that may contribute to such a fatal event. METHODS: We analyzed the tapes of eight patients (seven men and one woman with a mean age of 66 +/- 8 years) who had ischemic sudden death during ambulatory electrocardiographic (Holter) monitoring. Four patients had unstable and four had stable angina; none was taking antiarrhythmic drugs. Twenty patients with angina and transient myocardial ischemia during Holter monitoring served as control subjects. Arrhythmias, ST segment changes and heart rate variability were analyzed by a computerized interactive Holter system. RESULTS: Five patients had ventricular tachyarrhythmias (ventricular fibrillation in three, ventricular tachycardia in two), and three had bradyarrhythmias (atrioventricular block in two, sinus arrest in one) as the terminal event; all eight patients showed ST segment shift (maximal change 0.46 +/- 0.16 mV; with ST elevation in two) that occurred 41 +/- 34 min (mean +/- SD) before sudden death. The standard deviation of normal RR intervals (SDNN) was 89 +/- 33 ms during the 10 +/- 6 h of Holter monitoring; 5 min before the onset of the fatal ST shift, SDNN measurements were significantly lower than during the initial 5-min period (48 +/- 10 vs. 29 +/- 9 ms; p=0.002). In control patients, the SDNN was 102 +/- 39 ms during Holter monitoring, whereas it measured 56 +/- 30 ms 5 min before the most significant episode of ST shift (p<0.01 vs. 29 +/- 9 ms [corrected] in the group with sudden death). CONCLUSIONS: Autonomic dysfunction, as detected by a marked decrease in heart rate variability, is present in the period (5 min) immediately preceding the onset of the ST shift precipitating ischemic sudden death. These data suggest that sympathovagal imbalance may trigger fatal arrhythmias during acute myocardial ischemia, thus resulting in sudden death.

Aged↗
PubMed1996

Consequences of coronary occlusion on changes in regional interstitial myocardial neuropeptide Y and norepinephrine concentrations.

An attempt to determine the consequences of prolonged ischemia on simultaneous regional changes in norepinephrine (NE) and neuropeptide Y (NPY) interstitial myocardial concentrations in a pig model in vivo was made. The aim of the authors was to investigate further the mechanism of the major NE release previously observed in perfused hearts preserved using a Langendorff technique. Regional myocardial ischemia was induced by ligation of the left anterior descending coronary artery (LAD) in ten anesthetized pigs. NE and NPY release was studied using interstitial microdialysis, a technique initially used to monitor neurotransmitter kinetics in brain dialysate samples. Four dialysis probes were implanted into the left ventricular wall of the beating heart. Two were implanted into the ischemic region (LAD) (for NE and NPY determinations, respectively) and the remaining two into the non-ischemic left circumflex coronary artery region (LCX). Dialysate NE and NPY concentrations, as indices of interstitial myocardial NE and NPY concentrations, were measured by HPLC and RLA, respectively. A slight but significant increase in NPY levels was observed in both territories (LAD: from 190 +/- 27 to 349 +/- 62 pmol/l, LCX: 146 +/- 30 to 257 +/- 52 pmol/l) suggesting moderate stimulation of cardiac sympathetic nerve activity following LAD occlusion. On the contrary, a marked but progressive increase in NE release was observed in the ischemic region (from 8.8 +/- 1.0 to 251.4 +/- 44.8 nmol/l), when NE levels in the non-ischemic region remained stable (from 10.3 +/- 2.1 to 11.0 +/- 1.9 nmol/l). These results demonstrate the utility of regional in-vivo myocardial NE and NPY monitoring using microdialysis. The strong and sustained NE accumulation occurring in the ischemic region is consistent with the hypothesis of a local non-exocytotic metabolic NE release in case of prolonged myocardial ischemia, when exocytotic release remain only minimal as attested by the slight increase in NPY observed.

Animals↗
PubMed1996

Inhaled nitric oxide as an adjunct to pulmonary thromboendarterectomy.

In chronic pulmonary vascular thrombotic disease, pulmonary thromboendarterectomy has proved to be effective in reducing pulmonary hypertension and improving gas exchange. However, persistent pulmonary hypertension and unrelenting reperfusion edema are the main causes of death. We report a case of pulmonary thromboendarterectomy followed by an immediate unfavorable postoperative course with acute and persistent pulmonary hypertension, gas exchange impairment, and heart dysfunction. In this particular case, inhaled nitric oxide was successfully administered.

Administration, Inhalation↗
PubMed1996

[Primary liposarcoma of the left ventricle. Apropos of a case and review of the literature].

Primary malignant myocardial tumours are rare and essentially sarcomas. The authors report a case of primary left ventricular liposarcoma which is the 18th reported case. The presenting signs were of cardiac failure. Metastases are common by the time of diagnosis. Surgical ablation, though rarely complete because of its myocardial localisation, is justified for precise histological diagnosis. The prognosis of these lesions is poor. Complementary treatment is rarely used. However, it should be proposed as surgery alone has been shown to have limited curative applications.

Adult↗
PubMed1996

[Prognostic significance of normal exertion myocardial scintigraphy in asymptomatic subjects with abnormal ergometric test].

AIM OF THE STUDY: ST-segment depression on exercise stress test (EST) is an independent predictor of future cardiac events. Nevertheless, in apparently healthy subjects without angina the occurrence of false positive results is frequent. Thallium myocardial imaging (TMI) may improve diagnostic and prognostic accuracy of EST. The aim of the present study was to assess the role of a normal exercise TMI for excluding a coronary artery disease in subjects with asymptomatic abnormal EST. METHODS: Subjects referred for TMI from 1/1980 to 5/1991 with an abnormal EST and without history of ischemic, congenital, or valvular heart disease or abnormal resting ECG were included into the study. 137 subjects (98 men, 39 women), mean age 53 +/- 8 yrs (range 37-74 yrs) were enrolled and followed-up for 6.4 yrs (range 3-13 yrs). Clinical indications for EST were: atypical chest pain in 56 (41%) cases, check-up in 52 (38%) cases, sport activity in 29 (19%) cases. All subjects had a maximal symptom-limited EST. Abnormal EST was defined by a horizontal or downsloping > or = 1 mm or upsloping > or = 1.5 mm ST-segment depression at 0.08 sec. from J-point, in at least 2 leads. EST was discontinued for fatigue in 129 (94%) cases, for ST-segment depression > or = 3 mm in 8 (6%) cases. None had chest pain during EST. All subjects selected for the study had normal TMI. Criteria for normal TMI were homogeneous Thallium uptake on postexercise images and a normal washout in the delayed images by qualitative analysis. Planar images were obtained in 118 (86%) cases, and tomographic SPECT images in 19 (14%). RESULTS: During the follow-up period no subject died for cardiac causes and only 9 subjects (1%/yr) had non fatal cardiac events: 4 (0.45%/yr) had a non fatal myocardial infarction (one subject had coronary angiography for postinfarction angina and subsequent 3 coronary bypass graft for multivessels disease), 2 subjects (0.2%/yr) became symptomatic for unstable angina (both had coronary angiography and subsequent PTCA for critical left main coronary artery stenosis) and 3 (0.34%/yr) developed stable angina (one had coronary angiography and subsequent bypass graft for a critical stenosis of left main coronary artery). Four further subjects died for non cardiac events. Comparing clinical data and TE results of subjects with and without coronary events, we found that some parameters were related to a higher incidence of cardiac events: hypertension (78% vs 31% respectively in subjects with and without cardiac events, p < 0.01), hypercholesterolemia (33% vs 4.7%, p < 0.01); > or = 2 conventional coronary risk factors (56% vs 17%, p < 0.02); and a slow regression of abnormal ST-segment depression during recovery (2.8 +/- 2 vs 1.5 +/- 1 min, p < 0.01). CONCLUSIONS: In conclusion, in subjects without typical chest pain and with abnormal asymptomatic EST, a normal exercise TMI identifies subjects with very low risk of future cardiac events (1%/yr). Our data suggest that subjects with abnormal asymptomatic EST should be routinely submitted to exercise TMI.

Adult↗
PubMed1995

Changes in patient treatment after abrupt closure complicating percutaneous transluminal coronary angioplasty: a historic perspective.

This study compares the incidence and management of acute closure complicating coronary angioplasty in three historic populations of patients having undergone the procedure at the same center: group 1 (n = 146 of 881) ("early years" of angioplasty, 1980 to 1986), group 2 (n = 113 of 1781) (bailout stenting learning curve, 1990 to 1992), and group 3 (n = 34 of 525) (1993). The incidence of acute closure decreased from group 1 (146 [17%] of 881) to groups 2 and 3 (147 [6%] of 2306); (p < 0.001). Management of the occlusion changed over the years, with less emergency coronary bypass surgery ([36%] 52 of 146, 15 [13%] 113, and 3 [9%] of 34), respectively, p < 0.01) and more repeat angioplasty (70 [48%] of 146; 87 [78%], of 113, and 30 [88%] of 34, p < 0.001). The use of prolonged inflations (> 10 minutes) and stenting increased from group 2 (15 [13%] of 113 and 16 [14%] of 113, respectively) to group 3 (12 [35%] of 34, and 10 [30%] of 34, respectively). In-hospital death occurred in 18 (12%) of 146, 7 (6%) of 113), and (2 (6%) of 34) patients in the three groups. Acute myocardial infarction decreased from 64% to 46% and 27%, respectively (p < 0.01). Overall, the number of patients free of events at hospital discharge increased from 38 (26%) of 146 to 53 (47%) of 113 (p < 0.001) and to 23 (68%) of 34 (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1995

Myocardial effects of experimental acute brain death: evaluation by hemodynamic and biological studies.

BACKGROUND: Because of problems concerning the functional quality of heart transplants, more and more interest has been focused on the physiologic changes occurring during brain death, one of the major possible contributing factors to the myocardial alterations. METHODS: The aim of this study was to describe the link between acute experimental brain death and myocardial metabolism. This was achieved by in vivo 3-hour hemodynamic and biological (myocardial lactate production) studies and then in vitro 6-hour phosphorus-31 nuclear magnetic resonance spectroscopy. Two groups of pigs were involved in the study: group I (n = 10) as control and group II (n = 10) as brain-dead animals. RESULTS: Within the first hour, we observed a strong increase in myocardial activity associated with the onset of myocardial lactate production, lasting 2 hours and corresponding to a myocardial anaerobic metabolism period. Despite the apparent normalization before excision of the hearts, phosphorus-31 nuclear magnetic resonance spectroscopy revealed a significant decrease in adenosine triphosphate levels in group II when compared with group I. CONCLUSIONS: We conclude that, in our study, acute experimental brain death is associated with an early and transient period of myocardial anaerobic metabolism and adenosine triphosphate consumption. These myocardial consequences of brain death could partially explain some observations of heart graft dysfunction.

Adenosine Triphosphate↗
PubMed1995

[A transient decrease in heart rate variability in patients with sudden "ischemic" death during Holter monitoring].

BACKGROUND: Mechanisms precipitating sudden death are poorly known, in spite of the importance to detect functional factors which may contribute to such fatal event. Aim of the study was to investigate the relationship between "ischemic" sudden death (ISD: arrhythmic death preceded by acute myocardial ischemia) and autonomic nervous system activity. METHODS: We analysed the tapes of 6 patients (pts) (5 males; 67 +/- 12 yrs) suffering ISD during Holter monitoring (HM). One pt had recent onset angina, 2 had unstable and 3 stable angina; none was taking antiarrhythmic drugs. Arrhythmias, ST segment and heart rate variability (HRV) were analysed by a computerized interactive HM system, in order to obtain data on transient ischemia and sympatho-vagal balance. RESULTS: Five pts showed ventricular tachyarrhythmias (2 VF, 3 VT), and 1 had a bradyarrhythmia (advanced A-V block) as the terminal event; all pts showed ST shift (max: 0.37 +/- 0.28 mV; 1 with ST elevation; 4 with anginal pain) 53 +/- 35 min before ISD. SD of normal R-R intervals (SDNN) was 112 +/- 26 msec in the 11 +/- 8 hrs of HM, whereas it was 97 +/- 48 msec in the initial hour and 59 +/- 21 msec in the initial 5 min segment. Measurements of SDNN showed a marked decrease 5 min before the onset of fatal ischemic ST shift: 32 +/- 14 msec (p = 0.003). Also, pNN50 (percent of adjacent R-R differing > 50 msec: marker of vagal activity) was significantly reduced before ISD, when compared to the initial 5 min segment (from 10 +/- 5 to 7 +/- 4%; p < 0.03). Such changes were not observed before uncomplicated (that is not associated with malignant arrhythmias) ST shift episodes during HM. CONCLUSIONS: Autonomic dysfunction, as detected by a marked decrease of HRV, is present in the period (5 min) immediately preceding the onset of ST shift precipitating ISD; simultaneous measurements of vagal signals showed similar changes. These data suggest that sympatho-vagal unbalance may trigger fatal arrhythmias during acute myocardial ischemia, hence resulting in ISD.

Aged↗