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Biomedical subjects

M Gueron

Publications and source records attributed to M Gueron.

At least 91 records · Page 5Linked to original sources
PubMed1981

Choice of electrocardiographic leads for recording the earliest QRS onset in noninvasive measurements.

A significant error may be introduced in intervals measured from the onset of the QRS if an electrocardiographic lead that does not record the earliest deflection is used. To ascertain to what extent the commonly used leads can be relied on to show the earliest QRS onset, 100 normal subjects and 219 patients with heart disease were studied by means of simultaneous recording of three leads: a right precordial lead chosen to show an rS configuration, lead II, and another limb lead chosen to show a qR configuration. Lead II most frequently showed a delayed QRS onset--in 34% of normal subjects and 36% of the patients. In the other limb lead the initial QRS deflection was delayed in 24% of the normal subjects and 23% of the patients. The QRS onset in the right precordial lead was never delayed in the normal subjects; however, it was delayed in this lead in 6% of the patients. The delays in each of the leads ranged from 5-20 msec. We conclude that while a right precordial lead is by far the most reliable single lead that can be used for interval measurements, simultaneous recording of a right precordial lead and a limb lead assures that recording of the earliest QRS onset in all cases.

Electrocardiography↗
PubMed1981

Cardiac tamponade in medical patients.

We reviewed the cases of 56 medical patients wih cardiac tamponade who were treated at the University of Cincinnati. A paradoxic arterial pulse was critical in the diagnosis because most patients did not have a small quiet heart, and blood pressure was often well maintained. Fifty-two of 55 patients had enlarged cardiac silhouette by chest radiogram; heart sounds were diminished in 19 patients; arterial systolic pressure was greater than or equal to 100 mm Hg in 35, and arterial pulse pressure was greater than or equal to 40 mm Hg in 27. Echocardiograms in 23 patients showed abnormally increased right ventricular dimensions and decreased left ventricular dimensions during inspiration, except in one patient with left ventricular dysfunction. The causes of cardiac tamponade were metastatic tumor in 18 patients, idiopathic pericarditis in eight and uremia in five; five cases of tamponade occurred after heparin administration in acute cardiac infarction. Myxedema and dissecting aneurysm each caused tamponade in two patients. Pericardiocentesis relieved tamponade initially in 40 of 46 patients; however, two suffered fatal complications. Pericardial resection was done in 18, including 12 of these 46.

Adolescent↗
PubMed1978

Haemorrhagic infarction of the myocardium in a newborn with haemoglobin H disease and erythroblastosis.

Extensive haemorrhagic myocardial infarction developed in a newborn, apparently as a result of anoxia due to erythroblastosis fetalis, associated with haemoglobin H disease. Acute massive myocardial infarction in the neonatal period is rare and usually is associated with congenital malformation of the heart or its blood supply. Neonatal myocardial infarction in the anatomically normal heart with normal coronary vessels, has been described in only 8 patients (1). The communication describes a newborn with acute haemorrhagic myocardial infarction due to anoxia believed to be caused by the combined effect of erythroblastosis fetalis and haemoglobin H disease.

Erythroblastosis, Fetal↗
PubMed1978

Systolic time intervals in children: normal standards for clinical use.

Systolic time intervals were measured in 253 normal children, with careful attention to precise recording and measuring techniques, to derive regression equations which could be used as reliable standards for clinical assessment of left ventricular performance in this age group. Using stepwise regression analysis, a highly significant correlation was found for electromechanical systole (QS2) and for left ventricular ejection time (LVET) with heart rate alone in both males and females, and age was not found to be a relevant variable. Similarly, for the preejection period (PEP) in males, heart rate was the only relevant variable. PEP in females showed a small but significant influence of age in addition to heart rate; in practice, this small influence can be neglected. Regression equations relating each of the systolic time intervals to heart rate alone were therefore derived for clinical use. The PEP/LVET ratio was found to be only weakly correlated with heart rate in males and with age in females, and in practice can be considered to be independent of these variables. The mean value of the PEP/LVET ratio and its standard deviation (0.30 +/- 0.04) can therefore be used for all children. We found that satisfactory recording of systolic time intervals can be obtained with little difficulty in almost all children using the techniques described. The method is therefore practical for clinical use in children, as it is in adults, and the normal standards derived in this study can serve as a reliable basis for its application.

Adolescent↗
PubMed1978

Congenital QT interval prolongation. A review with a survey of three families.

The prolonged QT interval syndrome without hearing loss (Romano-Ward syndrome) is described in three families with 48 affected members. Syncope or dizziness caused by different ventricular tachyarrhythmias were the presenting symptoms in the symptomatic patients. Four of the subjects died suddenly. Right stellate ganglionectomy was performed in one patient in order to abolish the ventricular dysrhythmia. beta-blockers are considered the drug of choice in patients with hereditary prolonged QT interval; if the beta-blockers fail to abolish the syncopal attacks of severe bradycardia complicates the clinical course, a pharmacological blockade of the stellate ganglia should be performed and its results carefully evaluated in order to establish whether a stellate ganglionectomy is justified.

Adult↗
PubMed1977

Parasympathomimetic action of scorpion venom on the cardiovascular system.

Although the precise mechanism of the cardiovascular effects in man evoked by the venom of the yellow scorpion has yet to be completely elucidated, previous studies indicate that excessive adrenergic activity is present in many of the cases. This report describes two patients in whom yellow scorpion sting was followed by bradyarrhythmia with varying degrees of atrioventricular block which promptly regressed after the administration of atropine; this is consistent with a direct parasympathomimetic effect of the venom or with a central effect producing increased vagal tone. It is suggested that the cardiovascular actions of the venom may represent a wide spectrum of effects on the autonomic nervous system, ranging from the predominantly sympathomimetic to the predominantly parasympathomimetic.

Adult↗
PubMed1976

Left ventricular diverticulum and mitral incompetence in asymptomatic children.

Two children with congenital apical left ventricular diverticulum and significant mitral incompetence are reported. The angiographic and anatomic findings of the few previously reported patients with congenital diverticula and aneurysm were analyzed and a new classification differentiating between the two is proposed. The clinical data analyzed in apical diverticula and aneurysm are similar to those patients with anomalous origin of the left coronary artery from the pulmonary artery. Left ventriculography is the best diagnostic tool. The place of surgery in the treatment of the congenital apical diverticula with or without mitral incompetence in asymptomatic children is not clear. Further observations are needed to reveal its natural history.

Angiocardiography↗
PubMed1975

Delayed hemopericardium following penetrating foreign body into the aorta.

A four and a half year old girl with delayed appearance of traumatic hemopericardium, detected radiologically despite misleading clinical manifestations, is presented. The presence of cardiomegaly and a needle in the right upper mediastinum on the chest roentgenogram and its partial motion together with diminished cardiac pulsations at fluoroscopy led to angiocardiography. The radiological demonstration of hemopericardium due to the needle penetrating the aortic root, enabled successful surgical intervention.

Aorta↗