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Biomedical subjects

A Biagini

Publications and source records attributed to A Biagini.

At least 91 records · Page 5Linked to original sources

Electrocardiographic monitoring: temporal versus spatial information and data processing.

In the diagnosis of ischemic heart disease, long-term electrocardiographic recording has several distinct advantages. It allows one to relate patient symptoms to cardiac disturbances and to detect asymptomatic events, furnishes the whole spectrum of electrocardiographic alterations accompanying ischemic attacks, reveals the possible ischemic genesis of dysrhythmias, and is the most suitable method to assess the acute and chronic effectiveness of treatment and the evolution of the disease. In addition to its valuable application in the screening and follow-up of ambulatory patients, its use in the Coronary Care Unit is of great interest, being in this context much more sensitive than visual electrocardiographic monitoring. In spite of these advantages, Holter monitoring has several limitations: the recording and replay systems are below recommended standards; the analysis of a single lead is responsible in most systems for the low sensitivity in detecting ischemia occurring in unexplored regions; the period of 24-48 hours, usually adopted for Holter monitoring, may not be sufficient for screening patients with suspected myocardial ischemia due to the unpredictable spontaneous variability of the disease; a common standard of analysis is still lacking and a reliable computerized analysis is needed to manage data overflow. In conclusion, although further research and technical developments are desired to improve reliability and data processing, the role of Holter monitoring appears essential in the ambulatory screening of patients with suspected ischemia for a better characterization of patients with ascertained myocardial ischemia, and for the evaluation of treatment and of the evolution of the disease.

Angina Pectoris, Variant↗

Unreliability of conventional visual electrocardiographic monitoring for detection of transient ST segment changes in a coronary care unit.

Visual monitoring at the central station of coronary care units (CCUs) may not adequately assess the presence and frequency of transient asymptomatic ST segment changes in patients with unstable angina. We have performed continuous 24-h electrocardiographic recordings over a total period of 50 days in 10 patients admitted to our CCU with frequent attacks of angina at rest. Over the corresponding period, at the central monitoring station (6 beds), the nursing-staff detected only 31 transient ischaemic episodes (27 with ST elevation, 4 with depression, 9 of which were asymptomatic). By contrast the retrospective analogue analysis of tapes identified 213 ischaemic episodes: 143 with ST elevation (greater than or equal to 0.2 mV) and 70 with ST depression (greater than or equal to 0.2 mV); usual CCU monitoring failed to report changes during 13 episodes (8 with ST elevation, 5 with depression) accompanied by anginal pain. When the tapes were played back in real time on a CCU monitoring scope, a cardiologist (who had the option of interrupting the play-back whenever tired) recognized 48% of the episodes when presented in groups of 4 and randomly positioned on the screen together with 2 other electrocardiographic tracings not related to the study; he recognized 92% of the episodes when only one ECG was presented on the screen. Thus conventional visual monitoring in a CCU considerably underestimates the incidence of transient ischaemic ST segment changes, some of which were accompanied by pain. This low rate of detection is the result of the presentation on the central monitoring station of several ECGs and of fatigue.

Adult↗

[Isosorbide dinitrate ointment in the long-term treatment of intermittent claudication].

We evaluated the long-term therapy with Isosorbide Dinitrate Ointment (ISDN-O): 300 mg daily on the painful leg area in 20 male patients (pts) affected by Intermittent Claudication. The efficacy of the treatment was assessed on the basis of the subjective evaluation of pain threshold (daily diary) and objectively by repeated treadmill stress tests performed by each patient at a constant speed, selected according to the severity of symptoms, and by the evaluation of changes both of the distance walked without symptoms (DWS) and of the maximal distance reached (MDR). The maximal duration of the test was 15 minutes independently from the speed. The reproducibility of treadmill tests and the acute effect of isosorbide dinitrate ointment administration were preliminarly evaluated in 2 groups of 5 patients each. The distance walked without symptoms and maximal distance reached in two control stress tests performed in two successive days were: distance walked without symptoms 37 +/- 29 vs 36 +/- 22 m (NS) and maximal distance reached 97 +/- 40 vs 98 +/- 37 m (NS). During the control period and 1 hour after the drug administration distance walked without symptoms was 34 +/- 31 vs 43 +/- 50 m (NS) and maximal distance reached 89 +/- 53 vs 97 +/- 57, (NS) respectively. In a group of 5 patients the effect of one month administration of placebo was evaluated: distance walked without symptoms was m 68 +/- 29 and m 104 +/- 62 and maximal distance reached was m 156 +/- 103 and m 188 +/- 97 basally and after 1 month of placebo (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Intravenous dl-carnitine fails to increase the double-product during atrial pacing in patients with effort angina. A double-blind randomized study.

Infusions of DL-carnitine are reported to improve the tolerance to atrial pacing of patients with angina pectoris. In the present study, six patients with angina of effort and triple vessel disease received two placebo and two carnitine infusions administered in a double-blind randomized fashion. Carnitine did not affect either the double product (heart rate X systolic blood pressure) at maximal pacing (ST depression: 2.3 +/- 0.2 mm, +/- SEM) or the tolerated pacing time. Intravenous carnitine, in the dose given, is of no therapeutic benefit in myocardial ischemia precipitated by tachycardia. It could be effective when free fatty acids are elevated as during catecholamine stimulation.

Angina Pectoris↗

Vasospastic ischemic mechanism of frequent asymptomatic transient ST-T changes during continuous electrocardiographic monitoring in selected unstable angina patients.

Asymptomatic episodes of ST segment and/or T wave changes are often reported during Holter monitoring in patients with angina pectoris. However, the interpretation of such changes is debated relative to silent myocardial ischemia. We studied 11 patients admitted to the CCU because of frequent episodes of unstable anginal attacks who had undergone repeated periods of Holter monitoring, characterized by predominantly occurring asymptomatic episodes of ST segment and/or T wave changes associated with less frequent typical anginal attacks. In a total of 89 days of Holter monitoring, the patients evidenced 520 episodes of transient ECG changes including 180 of ST elevation, 73 of ST depression, and 267 of T wave alterations. Only 12% of episodes were symptomatic. Coronary injection during asymptomatic ST-T changes was performed in eight patients. In six it was possible to document spontaneous coronary spasm. In seven patients ergonovine administration induced anginal pain, ST-T changes, and coronary spasm. In all patients the anginal attacks completely disappeared with medical treatment and the asymptomatic episodes were abolished in six and reduced in four. Our findings support the hypothesis that in certain selected unstable anginal patients, transient asymptomatic ECG changes are caused by acute myocardial ischemia.

Angina Pectoris↗

[The role of spasm in angina pectoris, myocardial infarction and sudden death. Indications for future research and treatment].

Recent concepts on the role of coronary artery spasm and other forms of vasoconstriction in coronary artery disease are studied with particular reference to episodes of transient ischemia and their therapeutic implications. The possible contribution of spasm and other obstructive mechanisms such as platelet agregation, to the different forms of angina, myocardial infarction and sudden death, is analysed in the light of clinical observations, some of which have not previously been reported. Based on these concepts and clinical considerations, new orientations for future research and treatment are suggested. In our series, long term treatment of coronary artery disease with the association of nitrate derivatives are suggested. In our series, long term treatment of coronary artery disease with the association of nitrate derivatives and calcium antagonists has led to a reduction in mortality and in the incidence of myocardial infarction over periods ranging from 2 to 4 years.

Angina Pectoris↗

HLA segregation of human T-cell subpopulation markers.

Antisera recognizing subsets of human T lymphocytes can be produced by planned immunizations involving HLA-A and HLA-B compatible donors. The reactivity of these antisera against some individuals of a population, but not others, show that they recognize a polymorphic cell surface component. The study of informative families shows the HLA linkage of at least some of these alloantigenic determinants.

Antibody Specificity↗

[Hourly distribution of episodes of angina at rest. Effect of medical treatment].

Aim of the study was to evaluate whether frequency of myocardial ischemic attacks at rest (IA) had any identifiable distribution during 24-hour periods. Two ECG leads were continuously recorded by an Oxford 4-24 tape recorder for a total of 148 days in 10 patients admitted to CCU because of frequent spontaneous anginal attacks. During 48 days, in absence of therapy, 682 IA were recorded (2.03 per patient per day). They showed a symmetrical bell-shaped distribution curve in the 24 hour periods with a peak occurring at 5 a.m. and 43% of IA from 0 to 6 a.m. Only 25% of IA was symptomatic with the lowest values (10%) between 2 and 6 a.m. Distribution of IA was independent from their distinctive electrocardiographic feature [ST (71%) or T changes]. During 100 days with therapy [Verapamil and/or Isosorbide dinitrate ointment) a marked reduction of episodes was observed (0.64 per patient per day), while their distribution, the incidence of different electrocardiographic patterns and percentage of symptomatic IA remained unchanged. Attenuated incidence, but inalterated distribution of IA with therapy suggest its possible effect on the threshold response of coronary smooth muscle to vasoconstrictor stimuli rather than its primary effect on pathogenetic factors.

Adult↗

[Intermittent claudication: topical treatment with isosorbide dinitrate ointment. Preliminary results].

Following the casual observation reported by one anginal patient of ours, of improvement of its claudicatio intermittens with application of isosorbide dinitrate ointment directly on the leg suffering pain, we undertook a study to assess the possible use of the drug in peripheral vascular disease in a group of 10 patients suffering of a severe form of claudicatio intermittens. The effect of the drug was tested 1) by the subjective valuation of the patient itself 2) by treadmill stress tests performed at constant rate. In this case were used as reference parameters the distance walked without any symptoms and the maximal distance reached by each patient. The treadmill stress test was performed in basal condition and after longterm administration of isosorbide dinitrate ointment 100 mg three times a day for 30-45 days. In 5 patients the control test was repeated twice in different days to evaluate the reproducibility of the measure that resulted good, while other 5 patients performed the test one hour following the application of the drug in order to assess a possible acute effect of the drug that was not present in any patient. All the patients noted an improvement in their walking capacity but only after 15-20 days of treatment. In basal condition the distance walked without any symptoms by the patients was on the average m. 51 (+/- 52) and the maximal distance reached was m. 143 (+/- 111), while after the treatment were m. 151 (+/- 136) and m. 384 (+/- 203) with a difference highly significative (p less than 0.05 and p less than 0.01 respectively). From our data although preliminary, it is apparent that longterm local application of isosorbide dinitrate is effective in the treatment of patients with peripheral vascular disease and that the action of the drug seems to be related to a local effect.

Administration, Topical↗

[Low reliability of ECG monitoring in CCU for detection of ischemic episodes (author's transl)].

In 10 patients with frequent anginal attacks admitted to CCU, 2-lead ECG Holter monitoring (H-M) was performed for a total of 10 days. The number of ischemic episodes detected by retrospective analysis of H-M was compared with the number detected on the basis of symptoms and continuous visual ECG monitoring in CCU (CCU-M) by highly trained staff. A total of 157 episodes was identified by H-M [82 ST elevation (ST), 15 ST depression (ST) and 60 t wave changes]. Only 15 of these episodes were detected by CCU-M (13 ST, 1 ST and 1 T wave changes) of which 12 were symptomatic. When 6 H-M ECGs were simultaneously displayed on an oscilloscope in real-time (as in CCU-M), one of the Authors was able to detect only 36% of the episodes, whereas the frequency reached 80% when the analysis was limited to one tape at the time. The results show the low reliability of the CCU-M in detecting ischemic attacks; this appears mainly related to the display of multiple tracings.

Angina Pectoris↗

[Analysis of Holter monitoring for detection of myocardial ischemia episodes (author's transl)].

While the use of the 24 hour Holter monitoring for the detection of the cardiac arrhythmias and conduction disturbances is well established, its applicability to the monitoring of the ST segment and T wave for the detection of myocardial ischemia is controversial. For these reasons the Holter monitoring is mainly confined to the detection of cadiac arrhythmias and is used in those centers where computer facilities are available. We proposed to record the electrocardiographic tape replayed at 60 times the real time on a direct recording ultraviolet oscillograph running at low speed obtaining a fast compact analogue representation of the Holter recording where the 24 hour Holter recording is compressed into cm 480 of paper. The analogue compact representation described allows an easy detection of the transient displacement of the ST segment and/or changes in the T wave amplitude and direction and/or QRS pattern all due to myocardial ischemia without the use of any expensive computer facilities.

Coronary Disease↗