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Biomedical subjects

D Tzivoni

Publications and source records attributed to D Tzivoni.

At least 127 records · Page 7Linked to original sources
PubMed1982

Cardiokymographic wall motion pattern in patients with acute myocardial infarction.

We studied 50 patients with acute myocardial infarction by cardiokymography to record anterior left ventricular wall motion. Systolic outward motion was observed in 46 of 50 patients (92%). Holosystolic outward motion was characteristic of acute anterior infarction (93%) and acute subendocardial infarction (89%) but was less common in acute inferior infarction (29%). Partial systolic outward motion was seen in 8 of the 14 patients with acute inferior infarction, but only in 2 of 36 patients with acute anterior and subendocardial infarction. Cardiokymographic abnormalities were seen in more precordial locations in acute anterior (80%) and subendocardial infarction (97%) than in inferior infarction (74%). Holosystolic outward motion was seen in 75% of all locations in acute anterior and subendocardial infarction and only in 23% in acute inferior infarction. Thus both the extent and the severity of abnormal systolic outward motion clearly separated inferior infarction from anterior and subendocardial infarction. Dynamic changes in wall motion contraction patterns were observed during the course of acute myocardial infarction; both improvement and deterioration were observed. Cardiokymography is a simple, non-invasive method to assess changes in left ventricular segmental wall motion in patients with acute myocardial infarction.

Aged↗
PubMed1982

A second zone of compensation during atrial premature stimulation: evidence for decremental conduction in the sinoatrial junction.

125 consecutive patients with premature atrial stimulation were studied. Three demonstrated sinus node return cycles that were fully compensatory following premature atrial stimuli delivered early in diastole. This second zone of compensation was unaccompanied by significant alterations in the post-return cycle lengths or in P-wave morphology of the return cycle. To account for the occurrence of a complete compensatory pause following very early premature atrial depolarizations, we consider the possibility that retrograde conduction of the early atrial premature depolarization (APD) in the sinoatrial junction was delayed for a sufficient length of time to allow the sinus node to depolarize spontaneously on schedule. Collision between the APD and sinus beat would then occur despite the marked prematurity of the APD. Thus, the early APD had encountered the relative refractory period of the sinoatrial junction, suggesting that decremental conduction takes place within the sinoatrial region in man. These findings imply that there is the potential for reentry in the region of the human sinoatrial junction.

Aged↗
PubMed1982

Atypical ventricular tachycardia (torsade de pointes) induced by amiodarone: arrhythmia previously induced by quinidine and disopyramide.

A 44-year-old woman is described in whom amiodarone, disopyramide, and quinidine, administered alone separately, induced atypical ventricular tachycardia (AVT, torsade de pointes). Following a closed mitral valvotomy, she received quinidine, 1.2 g/day, without interruption for 17 years. Because of a recurrence of paroxysmal atrial fibrillation, the dose of the drug was increased to 1.4 g/day; 24 hours later AVT with syncope developed but responded promptly to atropine. Two years later, 24 hours following an increase in the dose of disopyramide from 300 to 600 mg/day, AVT with syncope occurred; isoproterenol abolished the arrhythmia instantly. Amiodarone was the third drug to induce AVT in this patient; she received 200 mg/day six days per week for six months. The dose was subsequently increased to 200 and 400 mg/day on alternate days, six days per week, and two months later AVT occurred. That time the only effective treatment was ventricular pacing.

Adult↗
PubMed1981

Ventricular pacing in atypical ventricular tachycardia.

Ventricular pacing was effective in controlling recurrent bouts of atypical ventricular tachycardia (Torsade de Pointes), in four patients. This arrhythmia was induced by quinidine or disopyramide therapy. Isoproterenol, which is the usually recommended therapy, was ineffective in two of the patients and was considered hazardous in two others. We consider ventricular pacing as a safe and reliable method for treatment of AVT, which should be applied if isoproterenol is ineffective or contraindicated.

Aged↗
PubMed1981

Acute myocardial infarction caused by blast injury of the chest.

A 51-year-old healthy man was hit in the chest by the shock-waves generated by an explosion, without being injured by any physical object. He felt immediate chest pain, but, in spite of electrocardiographic tracings highly suspicious for an acute anteroseptal infarction in the emergency room, he was discharged from hospital. The electrocardiogram recorded three weeks later was pathognomonic of anteroseptal infarction. Coronary arteriography performed four months later showed a complete obstruction of the left anterior descending coronary artery, with retrograde filling from the right coronary artery. It is assumed that the myocardial infarction was caused by the blast injury which induced an intimal tear and/or a subintimal haemorrhage in the left anterior descending artery with subsequent thrombosis. The lack of atherosclerosis in any other coronary arteries in this patient is noteworthy.

Blast Injuries↗
PubMed1981

Relationship between ventricular arrhythmias detected by ambulatory ECG monitoring and subsequent sudden cardiac death.

During the years 1971-1974, ambulatory ECG monitoring (AEM) during everyday activities was done in 888 consecutive subjects. Half of them were patients who suffered from chronic ischemic heart disease (IHD), while in the others no symptoms or signs of this disease were found. Ventricular arrhythmias (VA) were detected in 196 subjects of the former and in 190 of the latter group. The Bureau of Statistics provided information concerning the individuals who died before December 31, 1976, the cause of their death and whether or not the death occurred in hospital or was 'sudden'. We found that during the follow-up period, the rate of sudden cardiac death among the patients with IHD in whom AEM detected VA was higher than in subjects without VA. In the former group, there were 12 sudden cardiac deaths among 196 patients, while in the latter there were only 4 out of 248, a statistically significant difference. Sudden cardiac death was more frequent in individuals without IHD if AEM disclosed VA (4 sudden cardiac deaths among 190 subjects), as compared to individuals without VA (no sudden cardiac deaths among 254 subjects).

Adult↗
PubMed1981

Etiology, warning signs and therapy of torsade de pointes. A study of 10 patients.

Torsade de pointes, also called atypical ventricular tachycardia (AVT), was diagnosed in 10 patients, nine on antiarrhythmic therapy and one with acute central nervous system damage. Four patients received quinidine and five disopyramide, either alone or in combination with amiodarone. AVT was dose-dependent in some, but in others, it started shortly after initiation of drug therapy (idiosyncrasy). All patients had QT prolongation longer than 0.60 second immediately before the onset of AVT. This measurement appeared to be a more sensitive predictor of the development of AVT than QTc prolongation or QRS widening. All patients also showed bradycardia before AVT onset. After therapy, the QT immediately decreased, while QTc and QRS remained prolonged for longer periods. Isoproterenol was effective in five of seven patients, but was contraindicated in two others. Ventricular pacing was used in four patients, including the two who did not respond to isoproterenol, and this abolished AVT promptly. Isoproterenol or pacing appear to be the therapy of choice for AVT, while the conventional drugs used to treat the usual form of ventricular tachycardia are not only ineffective, but even contraindicated.

Adult↗
PubMed1981

The use of thallium 201 myocardial imaging to exclude myocardial infarction after dissection in congenital coarctation of the aorta.

The use of a mobile gamma camera with thallium 201 myocardial imaging is described to exclude myocardial infarction in a patient admitted to the coronary care unit in shock and with clinical, enzyme, and ECG changes consistent with infarction. The patient suffered from acute aortic dissection associated with congenital coarctation of the aorta. The myocardial scan excluded transmural myocardial injury.

Adult↗
PubMed1981

Diagnosis of coronary artery disease by multigated radionuclide angiography during right atrial pacing.

Right atrial pacing in conjunction with radionuclide angiography was used as a method to augment gradually myocardial oxygen demand in seven normal subjects and 11 patients with angiographically documented coronary artery disease (CAD). In five of the seven normal subjects the ECG during atrial pacing was normal and falsely pathologic in the two others; in all seven the ejection fraction (64 +/- 8 percent) did not change during the pacing. The atrial pacing was positive in seven of the eleven patients with CAD and falsely negative in four. In comparison, nine of these patients had more than 15 percent reduction in ejection fraction, while only two were regarded as negative. A maximal decrease of 31 percent in the average ejection fraction was observed in CAD patients at a pacing rate of 160/min. Wall motion pattern remained normal in all seven normal subjects, while new wall motion abnormalities developed during the atrial pacing in nine of the 11 CAD patients. We concluded that changes in ejection fraction induced by atrial pacing are sensitive indicators of myocardial ischemia. In patients with CAD, ejection fraction falls during pacing compared with normal subjects in whom ejection fraction remains unchanged.

Adult↗
PubMed1981

Disopyramide-induced Torsade de Pointes.

Recurrent ventricular tachycardia (torsade de pointes) is a serious and sometimes fatal arrhythmia occurring usually with quinidine therapy. Four patients experienced ventricular tachycardia after receiving conventional doses of disopyramide phosphate (600 mg/day) for recurrent atrial fibrillation-two of them in combination with amiodarone hydrochloride. Isoproterenol hydrochloride infusion was effective in three patients, while ventricular pacing promptly abolished ventricular ectopic beats and the ventricular tachycardia in the fourth patient. Torsade de pointes is more likely to occur in patients with severe repolarization delay and sinus bradycardia or atrioventricular block, and its appearance in four patients within a period of nine months after the introduction of disopyramide treatment in our service raises the possibility that this is not a rare complication of this drug, especially if used in combination with other QT interval-prolonging agents.

Aged↗
PubMed1980

The resting cardiokymogram: distribution of morphologies in normal patients and in patients with coronary heart disease.

The cardiokymograph, a relatively new noninvasive device capable of recording anterior left ventricular segmental wall motion, was used to evaluate the frequency and type of wall motion abnormalities in 25 normal patients and in 109 patients with ischemic heart disease. Of the 25 patients with normal coronary arteries and normal left ventriculograms, 24 had smooth systolic inward motion which morphologically resembles the normal pattern of systolic shortening as measured in experimental animals by various length gauges. In patients with angiographically established coronary artery disease but normal left ventriculograms and no previous myocardial infarction (MI), systolic outward motion was significantly more common than in normal patients. The most common systolic outward motion pattern seen in this group was partial outward motion characteristic of early stages of myocardial ischemia in experimental animals. In contrast, holosystolic outward motion, characteristic of severe ischemia in animals, was seen most commonly in patients with MI (73% anterior vs. 28% inferior). Thus, holosystolic outward motion was characteristic of MI especially when acute and involving the anterior wall, while partial systolic outward motion was the more common pattern in ischemic heart disease without MI, and systolic inward motion was the pattern most commonly seen in normals.

Coronary Disease↗
PubMed1980

Electrocardiographic characteristics of neurocirculatory asthenia during everyday activities.

We describe the electrocardiographic changes during everyday activities recorded by ambulatory electrocardiographic monitoring in 67 patients with neurocirculatory asthenia. The findings were compared with the results of ambulatory monitoring in 33 healthy controls. We observed episodes of sinus tachycardia > 120/min unrelated to effort in 60 of the patients, 35 had frequent episodes of pronounced sinus arrhythmia, 16 showed transient ST depression, and six transient ST elevation. All these changes appeared during the patients' routine activities, without any unusual exertion and frequently at rest. Periods of sinus tachycardia and sinus arrhythmia were recorded from the patients during sleep. Cardiac arrhythmias, especially ventricular premature beats, were also much more common in those with neurocirculatory asthenia than in the control subjects. These findings indicate that ambulatory electrocardiographic monitoring provides important information on the electrocardiographic characteristics of patients with neurocirculatory asthenia and helps to establish this diagnosis in obscure cases.

Activities of Daily Living↗
PubMed1980

Analysis of cardiac kinetics: use of a new photo-optic technique.

The photokymograph (PKG) is a new noninvasive instrument that can record segmental myocardial wall motion from self-illuminated images such as are produce; by fluoroscopy, cine ventriculography, two-dimensional sonography, and 99mTc scintigraphy. The PKG can be calibrated to provide amplitude of myocardial tissue motion. The recordings of segmental wall motion obtained closely resemble those recorded by established techniques, both during control state and during ischemic episodes. Regression analysis was performed to compare PKG recordings with frame by frame analysis of left ventriculograms (0.98) and with M-mode echo derived from two-dimensional images (r = 0.97). The PKG has some distinct advantages over existing techniques used to analyze segmental wall motion: it is inexpensive, usable simultaneously over multiple areas, analyzes individual beats, and is not restricted to any particular myocardial wall or any particular angle of motion.

Echocardiography↗
PubMed1980

Noninvasive diagnosis of coronary artery disease: the cardiokymographic stress test.

Stress-induced abnormalities of regional left ventricular wall motion were assessed by cardiokymography (CKG) during the course of maximal treadmill exercise tests in 157 patients, of whom 122 subsequently underwent coronary angiography. Seventy patients had significant angiographic coronary artery disease and 52 were normal. Forty-one of the 70 patients developed greater than 0.1 mV ST-segment depression (ECG sensitivity 59%) and 52 of 70 patients developed abnormal systolic outward motion by CKG (CKG sensitivity 74%). Among the 52 normals, 36 had negative ECG stress tests (ECG specificity 69%) and 49 had normally sustained systolic inward motion by CKG (CKG specificity 94%). The stress CKG was normal in 15 of the 16 false-positive stress ECGs; the stress ECG was correctly normal in two of the three false-positive stress CKG tests. Only one normal patient had concordantly false-positive ECG and CKG tests. The predictive accuracy of concordant ECG and CKG interpretations was, therefore, higher than either test alone. These data suggest that regional wall motion abnormalities, which are sensitive and specific markers of myocardial ischemia, may be detected noninvasively by CKG. We concluded that CKG helps identify false-positive and false-negative ECG stress tests and improves the diagnostic accuracy of stress testing for detection of coronary artery disease.

Adult↗