Biomedical subjects
Publications and source records attributed to F Orzan.
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To aid in the study of coronary artery disease, 57 patients with complete left bundle branch block underwent clinical evaluation, treadmill exercise testing and cardiac catheterization. The patients were classified into two groups according to coronary angiographic findings: 30 patients with significant stenosis (70 percent or greater luminal narrowing) of at least one major vessel and 27 with no significant coronary artery disease. There was no difference in age, presenting symptoms or previous medical treatment between the two groups. There were more men in the group with coronary artery disease. Exercise-induced S-T changes were similar in the two groups; the sensitivity and specificity of these changes for the diagnosis of coronary artery disease were unacceptable irrespective of the criterion chosen. With additional S-T depression of either 1 or 2 mm below the baseline value, the predictive accuracy was only 53 percent. Combined exertional chest pain and 1 mm S-T depression increased the predictive accuracy of exercise testing to 71 percent. These data indicate that exercise-induced electrocardiographic changes do not facilitate detection of coronary artery disease in patients with complete left bundle branch block.
An 8 year-old boy had extensive electrophysiological evaluation of his recurrent supraventricular tachycardias. His ECG never showed delta waves but intracardiac stimulation and recording disclosed the following (1) eccentric retrograde atrial activation; (2) increased cycle length and retrograde conduction time following the development of right bundle-branch block; (3) constant retrograde conduction time for increasingly premature ventricular stimuli; (4) atrial captures by ventricular stimuli when the atrioventricular-His pathways were refractory; and (5) no delta waves upon stimulation of the atrial input site of the anomalous pathway. A diagnosis of reciprocating tachycardia involving retrograde conduction through an accessory pathway was made. Reciprocating tachycardias involving a unidirectional retrograde anomalous pathway can be easily misdiagnosed as atrioventricular node reentrant tachycardias if no evidence of preexcitation can be found, particularly if the anomalous pathway is on the right side. In order to exclude the participation of a concealed unidirectional anomalous pathway in a patient's reentry tachycardia, a complete map must be made of right and left atrial endocardial activity.
A patient developed oliguria, peripheral edema, and dyspnea 5 days after mitral valve replacement. Chest roentgenogram and echocardiogram suggested pericardial effusion. Although pulsus paradoxus was absent, cardiac tamponade was suspected and subsequently confirmed during pericardiocentesis. Before pericardiocentesis right and left ventricular diastolic pressures were equal, as well as intrapericardial and right atrial pressures. The left ventricular cavity was reduced in size on the echocardiogram. Interventricular septal motion was normal. Pericardiocentesis normalized the hemodynamics and allowed the left ventricle to reexpand. Certain atypical features are tentatively explained as the combined effect of constrictive and effusive components caused by intrapericardial hemorrhage.
Two cases of horseshoe lung are described; one was suspected and the other was diagnosed preoperatively. Both underwent successful surgical treatment. The embryology of this anomaly is briefly reviewed with reference to the closely related scimitar syndrome (anomalous venous return of right lung to inferior atriocaval junction). Diagnostic studies are discussed with stress on the need for a thorough functional evaluation of both the heart and lungs before the surgical indication is made.
A case of bilateral bundle branch block is described with the following features: -- 2nd degree infranodal AV block due to bilateral, intermittently synchronous "phase 3" bundle branch block; -- occasional AV conduction failure due to concealed His bundle extrasystoles; -- right bundle branch block pattern due to retrograde activation from the left bundle branch; -- QRS complexes having normal duration due to uniform slow conduction in both bundle branches; -- Wenckebach phenomenon in the right bundle branch; -- concealed conduction in both branches. The above interpretations are based on the use of His bundle recordings, results of right atrial stimulation and of pharmacological testing. Determinations of the lengths of all H--H intervals, whether H was followed by a ventricular response or blocked, permitted insight into the mechanism of 2nd degree AV block with varying (right and left) bundle branch block.
Recognition of thrombosis of a Björk-Shiley aortic valve prosthesis 4 years after insertion in a patient was based upon sudden clinical deterioration, loss of prosthetic sounds, and development of new stenotic and regurgitant murmurs. Thrombotic fixation was confirmed by diagnostic alterations on the echocardiogram. All manifestations reverted to normal after successful surgical debridement of the prosthesis. Echocardiography is a valuable noninvasive adjunct in the differential diagnosis of prosthetic valve malfunction.
A case of recurrent paroxysmal ventricular tachycardia with retrograde Wenckebach block and reciprocal beats was studied with His bundle electrogram and right ventricular stimulation. Reentry was reproduced whenever retrograde ventriculo-atrial conduction time reached a critical value. Concealed reentry was also demonstrated and shown to be responsible for the dropped beats of the Wenckebach sequence.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Two unusual cases of traumatic aneurysm of the aorta are described. Both presented several days after thoracic trauma sustained in a car accident. The presenting features were progressing dysphagia and displacement of the oesophagus in the first case and a coarctation-like syndrome in the second. Diagnosis was confirmed in each case by aortography and emergency resection of the aneurysm with a dacron prosthesis was carried out. Aortic rupture should be considered in all cases of thoracic trauma, especially when severe, even several days after the trauma itself. Patients should be evaluated with serial chest roentgenograms and an aortography should be performed in any suspicious case. Treatment is surgical and the operative mortality and morbidity is acceptably low.