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Biomedical subjects

M Condorelli

Publications and source records attributed to M Condorelli.

At least 253 records · Page 14Linked to original sources
PubMed1981

Mechanisms underlying systemic hemodynamic responses to experimental coronary artery occlusion. A preliminary study with hexamethonium.

The hemodynamic changes induced by coronary occlusion were investigated in anesthetized dogs. Coronary occlusion elicited an immediate but transient increase in the systemic blood pressure and in the vascular resistance of the hind limb perfused at constant flow. Thereafter, systemic hypotension and vasodilatation in the perfused region were observed. Vagotomy abolished the initial increase of the systemic and perfusion pressure and reduced significantly the late vasodilator response both systemically and in the perfused hind limb. After the subsequent administration of hexamethonium the vasodilatation in the hind limb was no longer manifest but the fall in blood pressure was unmodified. These results seem to suggest that multiple mechanisms are involved in the hemodynamic response to coronary occlusion.

Animals↗
PubMed1981

Clinical hemodynamic and angiographic findings in 94 patients with old myocardial infarction. Comparison with 79 patients with coronary artery disease and no myocardial infarction.

Clinical, hemodynamic, coronary arteriographic, and ventriculographic findings of 94 patients (pts) with coronary artery disease (CAD) and old myocardial infarction (MI) have been described and compared with those of 70 pts with CAD and no previous MI. Pts with old MI presented a more compromised functional and hemodynamic status, with a higher incidence of NYHA class III-IV pts (40%), symptoms of left ventricular (LV) failure (31%), cardiomegaly (70%), higher left ventricular end-diastolic pressure (LVEDP) (19.6 +/- 9.6 mmHg, p less than 0.05), compared with 32%, 22%, 54% and 16.0 +/- 6.8 mmHg respectively in CAD pts with no MI. MI pts presented more severe CAD, higher incidences of three vessel disease (56%, p less than .005) and of left anterior descending (LAD) (34%) and right coronary artery (RCA) (36%) occlusions, compared with 34%, 6%, and 9% respectively in pts with no MI. Furthermore, pts with old MI showed more diffused and severe LV segmental wall contraction abnormalities, with higher frequencies of LV aneurysm (31%) and of pts with asynergy of more than 2 LV segments (26%), compared with 1% and 3% respectively in pts with no MI. Within the group with old MI, LVEDP was higher in pts with anterior (A) (22.0 +/- 11 mmHg, p less than .02) and anterior ł diaphragmatic (AłD) (21.5+/- 7.9 mmHg, p less than .05) MI, compared with pts with diaphragmatic (D) MI (16.6 +/- 7.1 mmHg); furthermore, LVEDP increase was significantly correlated with the severity and the extent of LV asynergy. In A and D MI, LAD and RCA stenoses or occlusions were prevalent respectively; pts with AłD MI showed larger numbers of coronary stenosis (3.05) and occlusions (1.05) per patient. The coronary artery supplying the infarcted area showed stenosis (greater than 75%) in 95.6% and was normal in 2.2% of cases. Thus, pts with CAD and old MI, and particularly of AłD and A MI, show a more compromised hemodynamic status and more severe degrees of CAD and of LV segmental wall contraction abnormality, which are responsible for their poor prognosis, compared to pts with CAD but no old MI.

Adult↗
PubMed1981

Severity of mitral regurgitation assessed by echocardiography. Reliability and limitations.

To assess whether echocardiography may represent a useful mean to evaluate the degree mitral regurgitation (DR), left ventricular diastolic internal dimension (LVIDd), left atrial dimension (LAD), and velocity of circumferential fiber shortening (Vcf) were compared to DR assessed by left ventriculography in 48 patients with primary (n = 21) and cardiomyopathic (n = 27) valvular incompetence. In patients with good left ventricular contractility, i.e. with Vcf values above 1.02, a significant positive linear correlation was found between LVIDd and DR (LVIDd = 5.38 + 0.45DR; r = 0.72; p less than 0.001). In contrast, in patients with depressed left ventricular function, i.e. with Vcf values below 1.02, LVIDd did not correlate to DR. In either group LAD and Vcf did not correlate to DR. Thus, echocardiography may provide useful semiquantitative information concerning DR only in patients with preserved left ventricular performance.

Cardiomegaly↗
PubMed1981

Arrhythmia control by cardiac stimulation.

Cardiac programmed stimulation in the control of tachyarrhythmias offers encouraging prospectives. We describe two devices which utilize radiofrequency as a means of synchronization and stimulation and can be triggered by the patient himself when tachycardia occurs. In addition we introduce a third anti-tachycardia device, completely automatic, which can be used in cardiologic departments. The first device described permits critical stimulation and can be programmed to deliver a single or double synchronized impulse. The second device, which utilizes the same implanted unit and electrode as used for critical stimulation, when activated searches the tachycardia interruption zone by scanning. The third device, based on the same principles, has a rate discriminator that activates the scanning stimulation. We treated 12 patients: 8 suffering from paroxysmal supraventricular tachycardia (4 with Wolff--Parkinson--White syndrome, 2 with intranodal reentry, 2 with brady--tachy syndrome); 2 patients with ventricular recurrent tachycardia; 1 with atrial flutter; and another with iterative junctional tachycardia. The follow-up varied for every patient from 6 yr to 3 mth.

Arrhythmias, Cardiac↗
PubMed1981

[Coronary artery disease (CAD) in females. Coronary arteriographic findings in 34 women and comparison with 184 males with cad].

We studied the clinical, hemodynamic and angiographic findings of 34 women (W) and of 184 men (M) with significant (greater than or equal 50%) CAD. W, compared to M, presented a higher incidence of systemic hypertension (p less than .025), while less frequent were among W smoking habits (p less than .001), history of old myocardial infarction (MI) (p less than .005), and patients in III-IV NYHA class (p less than .025). Left ventricular (LV) dP/dt was higher in W than in M (p less than .005). At coronary arteriography, single vessel disease (SVD) was more frequently found in W than in M (70% vs 23%, respectively, p less than .001); this findings was more evident in patients under 50 years of age (100% vs 30%, respectively, p less than .055). Prevalence of left anterior descending (LAD) over right (RCA) and circumflex (Cx) coronary artery stenoses was more marked in W than in M, especially in patients under 50 years of age (SVD of the LAD in 67% and of RCA in 33% of young W). Poor angiographic run-off of LAD was found in 21% of W, and only in 10% of M. In 2 of the 3 W with poor run-off of LAD operated on, a coronary bypass on the distal LAD was no technically feasible. At left ventriculography, a lower frequency of LV segmental wall motion abnormalities was found in W than in M, especially in patients with no history of MI (p less than .001). In summary, W with significant CAD, compared to age matched M, presented in our experience with a higher frequency of SVD and of LAD stenoses, and with a better LV contractile performance at left ventriculography. Furthermore, in W LAD more frequently showed a poor angiographic run-off. Such findings may bear important implications on the indication and results of coronary surgery in W with CAD.

Adult↗
PubMed1981

[Long-term electrical stimulation of tachycardias: control by ambulatory electrocardiographic monitoring (author's transl)].

The Authors suggest a new method, elaborated by their own, for long-term antiarrhythmic stimulation. They used ambulatory electrocardiography in order to evaluate the results. It consists of a radio frequency device for synchronization and stimulation, and allows the scanning stimulation of all the cycle of tachycardia, with automatic search for the zone of interruption. The stimulatory is carried by the patient, who must set it in motion at the onset of the tachycardia. Preliminary results show the efficacy of the method; Holter monitoring seems to be the best guide to the development of a satisfactory implantable automatic tachycardia-terminating pacemaker.

Ambulatory Care↗
PubMed1981

[Familial sudden death in preexcitation syndrome. Surgical interruption of the anomalous pathways in two brothers (author's transl)].

We describe the results of surgical dissection of multiple accessory pathways in two brothers. A significant family history of pre-excitation syndrome was present: two children died suddenly and at the autopsy of one of them an accessory atrioventricular connection was found. In the first patient the preoperative electrophysiologic study showed anterior septal and posterior septal accessory pathways, and enhanced conduction in the A-V node. The second patient had the following anomalous connections: enhanced conduction in the A-V node; anterior septal, posterior septal and right lateral accessory pathways; Mahaim fiber. Intraoperative mapping, performed during pacing from different sites at different cycle length, was used to define the atrial and ventricular insertions of the accessory pathways as well as to confirm the surgical success.

Adolescent↗
PubMed1980

Globin chain synthesis in single erythroid bursts from cord blood: studies on gamma leads to beta and G gamma leads to A gamma switches.

Erythroid bursts from cord or adult blood were grown in methylcellulose cultures (3 international units of erythropoietin per plate). On day 13, single bursts were picked up and reincubated for 16-24 hr with [3H]leucine. Radioactive globin chains [alpha,beta,G gamma, and A gamma (Ala-136)] were analyzed by either isoelectric focusing on polyacrylamide gels and fluorography or carboxymethylcellulose chromatography. In all cases, alpha to non-alpha globin radioactivity ratios were close to 1. In single cord blood bursts, the values of both gamma-to-beta and G gamma-to-A gamma ratios were spread over a large spectrum and further characterized by a continuous rather than a bimodal distribution. Morever, the G gamma-to-A gamma ratios demonstrated in single bursts appeared to be directly correlated with the respective gamma-to-beta ratios. These data suggest that both the gamma leads to beta and the G gamma leads to A gamma switches are mediated via mechanisms modulating the relative activities of the different genes in the non-alpha globin gene cluster rather than via selection of clones committed to the preferential synthesis of beta and A gamma globins. In contrast with the results obtained with cord blood, individual adult blood bursts synthesize a lower and hence relatively more uniform amount of gamma globin chains.

Erythropoiesis↗
PubMed1980

Effects of intravenous disopyramide on myocardial function in patients with different degrees of cardiac failure.

The effects of intravenous disopyramide phosphate on myocardial function were evaluated by non-invasive indices of cardiac performance (systolic time intervals, STI) in 15 patients with atherosclerotic heart disease and different degrees of cardiac failure. Disopyramide (1.5 mg/Kg) was given intravenously over a period of 5 min. This drug induced in patients in I-II classes of NYHA a significant decrease of LVETc, while PEP, ICT, and PEP/LVET ratio rose significantly. STI were affected much more markedly in patients in III-IV classes of NYHA. Particularly affected were contractility indices (PEP, ICT, PEP/LVET), which were reduced significantly more in patients in III-IV classes as compares to patient in I-II classes. In contrast, LVETc, which correlates to stroke volume and cardiac output, was similarly worsened by the drug in the 2 groups of patients. Therefore, this study shows that disopyramide has relevant depressant effects on myocardial performance, simultaneously reducing stroke volume and contractility, and that the effect on contractility is more marked in patients with severe left ventricular impairment.

Arrhythmias, Cardiac↗
PubMed1980

Myocardial hypertrophy in the rat. Correlation between two experimental models.

Two different conditions responsible for cardiac hypertrophy in the rat were investigated: the first one is isoproterenol-induced myocardial infarct, the second is exposure to hypoxia (0.42 atmospheres/24 h) in hypobaric chamber. To demonstrate that in both experimental models stimulation of protein synthesis is an absolute requirement to induce cardiac hypertrophy, a variety of techniques were employed including: evaluation of dry heart weight value, concentration of radiothallium (201T1) in the heart and effects of inhibitors of protein synthesis (Puromycin). Experimental results have showed: (A) a significant increase (p<0.001 as compared to control group) of dry heart weight values both in isoproterenol-treated and hypoxic rats; (B) a significant increase over control group (p<0.001) in myocardial 201T1 concentration in isoproterenol-treated rats; (C) total inhibition of cardiac hypertrophy in Puromycin treated group subjected to hypoxia. Finally, on the basis of different mortality observed in infarcted (85.0%) or hypoxic (5.0%) rats treated with Puromycin (40 mg/Kg body weight i.p.) a different role of cardiac hypertrophy in 2 experimental conditions is postulated: in the case of infarct-like lesions the cardiac hypertrophy has compensatory significance; under hypoxic stimulus is only due to increased cardiac work.

Animals↗
PubMed1980

Hemoglobin synthesis in individual bursts from normal adult blood: all bursts and subcolonies synthesize G gamma-and A gamma-globin chains.

Gamma-globin chain synthesis has been evaluated in individual bursts and subcolonies that were generated by normal adult blood BFU-Es in methylcellulose cultures containing semipurified erythropoietin (Ep) and then analyzed via either isoelectric focusing (IEF) of globin chains or immunofluorescence techniques. At variance with previously reported results, based on plasma clot culture and immunofluorescence, all bursts and subcolonies analyzed synthesize gamma-globin chains. Identification of gamma-chains has been confirmed by preparative IEF of HbF, followed by either carboxymethylcellulose chromatography or IEF analysis of the resulting globin chains. In all bursts analyzed, the relative synthesis of the two types of gamma-globin chains (G gamma and A gamma) shows an adult ratio (i.e., approximately 1:1). The results obtained via IEF have been confirmed by immunofluorescence studies, which apparently showed presence of at least some HbF-positive cells within all scrutinized bursts or subcolonies. The significance of these studies is discussed in the light of current hypotheses on mechanism(s) underlying HbF synthesis in normal adults.

Cells, Cultured↗
PubMed1980

Effects of antiplatelet and calcium antagonist drugs on infarct size in rats.

The authors performed the experimental model of infarct-like myocardial lesions in rats treated with large doses of ISP. Myocardial necrosis was assessed on the basis of serum enzyme changes as well as of gross and microscopic findings. The infarct size was measured by a direct enzymatic method assaying creatine kinase (CK) depletion in infarcted myocardium. Pretreatment of the infarcted rats with antiplatelet (Lysin Acetyl Salicylate) or calcium antagonist drugs (Verapamil or Nifedipine) allowed the reduction of the necrotic area. Since a smaller size of infarct was achieved through different types of interventions it should be suggested that ISP-myocardial damage is due to several effects of the drug involving metabolic, vascular and/or coagulative patterns.

Acute Disease↗