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Biomedical subjects

R Jonasson

Publications and source records attributed to R Jonasson.

32 records · Page 2Linked to original sources
PubMed1981

Aortic valve replacement in patients over 70 years.

Twenty-seven patients 70 years of age or more were operated upon with aortic valvular replacement with an early mortality rate of 7%. No more patients died during a mean follow-up period of 28 months. The Björk-Shiley standard tilting disc valve was implanted in 15 cases and the new convexo-concave model in 12 cases. Sixty-seven per cent of the patients had narrow aortic roots (21 and 23 mm prosthesis diameters) compared with 40% of younger patients. Thrombo-embolic complications occurred in 2 patients who had not received anticoagulant treatment. No such complications were recorded in the remaining 23 surviving patients treated with anticoagulants. All the surviving patients (except one who was re-operated because of a thrombotic encapsulation of the disc) were markedly improved postoperatively. High age alone is no longer an absolute contra-indication for aortic valve replacement. The convexo-concave Björk-Shiley tilting disc prosthesis is suitable in these patients because of its low resistance of flow at small diameters. The importance of anticoagulant treatment even in elderly patients is emphasized.

Age Factors↗
PubMed1981

Haemodynamic changes after tricuspid valve surgery. A recatheterization study in forty-five patients.

Changes of the central haemodynamics at rest and during exercise were evaluated in 45 patients who underwent tricuspid valve surgery. Tricuspid valve disease was associated with left heart valvular lesions in 42 patients, while isolated tricuspid valve lesions were present in 3 patients. The pre-operative evaluation showed marked impairment of cardiac function expressed by cardiomegaly, low physical working capacity, hypokinetic central circulation, elevated right atrial pressure and pulmonary hypertension in the majority of patients. Nineteen patients underwent tricuspid valve replacement and 26 tricuspid annuloplasty. The left heart valvular lesions were corrected by prosthetic valve replacement in all patients but one, who underwent mitral commissurotomy. The Björk-Shiley tilting disc valve prosthesis was used for all valve replacements. At postoperative evaluation the patients were classified in 3 groups: (1) Group TVR- 19 patients with well-functioning tricuspid valve prostheses; (2) Group TAP - 16 patients with good functional results in tricuspid annuloplasty; and (3) Group TAP-Failure - 10 patients in whom significant tricuspid incompetence was observed. The overall response to surgery in groups TVR and TAP was about the same, leading to an increase in working capacity and cardiac output and a decrease in heart volume, right atrial pressure and pulmonary hypertension. In the TAP-failure group, this response was limited to an increase in cardiac output and mainly attributable to the corrected left heart lesions. Sustained pulmonary hypertension, failing left ventricular myocardium, residual left heart lesions and anatomical tricuspid valve changes were the likely causes of TAP-failure, which could not be predicted from the pre-operative evaluation.

Adult↗
PubMed1980

Electrocardiographic diagnosis of ventricular septal infarction.

To find electrocardiographic criteria for ventricular septal infarction, two series of ECGs were studied, all without fascicular/bundle branch block and complete heart block. One series consisted of the ECGs recorded at thallium-201 scintigraphy in 49 patients 2-3 weeks after an acute myocardial infarction (AMI): in this series the 14 patients with a defect in the septal wall of the left anterior oblique view were compared with the 35 without. The other series consisted of the last premortal ECGs in 20 AMI patients with and in seven without a septal involvement of the infarct at autopsy. The best criterion from earlier literature ws absence of a q wave in lead V6, showing a sensitivity of 53% in the combined scintigraphy and autopsy series. The predictive value of a positive test was 75%. The very first QRS vector in the frontal plane tended to discriminate better than absence of a q in lead V6. With a similar predictive value, 71%, the sensitivity of a deviating vector (+ 120 degrees to -60 degrees and -120 degrees to -180 degrees) was 65% in the combined scintigraphy and autopsy groups. Most of the patients with a deviating vector showed this on admission. The clinical importance of an early diagnosis of septal involvement in AMI remains to be settled.

Adult↗
PubMed1980

Thallium-201 scintigraphy after acute myocardial infarction.

Fifty-five patients with acute myocardial infarction were examined with thallium-201 scintigraphy before discharge from hospital. Fifty-one showed significant scintigraphic defects. The number of abnormal Q waves in a 12-lead ECG but not the maximal ASAT value for each patient were correlated to the total estimated image defect. Mortality during the follow-up period of 14-28 months was not related to the estimated total image defect, but the two early deaths occurred among patients with the most dilated left ventricles.

Adult↗
PubMed1980

Exercise electrocardiogram in patients with normal and abnormal coronary arteriogram.

The predictability of normal and significantly abnormal coronary arteriogram from history, symptoms during exercise test and post exercise ECG changes was examined in seventy patients with chest pain consistent with effort angina. The combined criteria (1) increasing chest pain until interruption of the exercise test plus (2a) appearance or increase of a biphasic T wave post exercise or (2b) a previous acute myocardial infarction, were found to have a sensitivity of 81% and a specificity of 94%. Substituting ST depression for the T wave criterion did not increase either figure, nor did adding ST depression as an alternative criterion to the T was biphasicity. As inspecting the T wave configuration is simpler than measuring the ST depression, T biphasicity seems to be an alternative to ST depression. The only factor found in all patients with abnormal coronary arteriogram was chest pain increasing continuously during the exercise test until its interruption. The pain pattern occurred only in 71% of patients with normal arteriogram, and thus the absence of this pain pattern may be used to avoid some normal coronary arteriographies.

Adult↗
PubMed1980

Comparison of Kay's and de Vega's annuloplasty in surgical treatment of tricuspid incompetence. Clinical and haemodynamic results in 62 patients.

This paper compares the late results of Kay's and de Vega's annuloplasty in the management of tricuspid incompetence. The operations were done in 62 consecutive patients during the nine-year period 1969-77 and included simultaneous correction of acquired valvular lesions (58/62) and congenital malformations (4/62). Kay's bicuspidalization and de Vega's annular plication were performed in 27 vs. 35 patients and these two groups were similar in the most important respects. Tricuspid regurgitation was recognized in 44/62 patients (71%) before surgery, whereas in 18/62 patients (29%) it was diagnosed at intra-operative exploration. The majority of cases (84%) were functional in origin and 16% had anatomical lesions causing or contributing to significant incompetence. Most of the patients (90%) belonged to functional class III or IV (N.Y.H.A.) before operation. The type of tricuspid repair had no bearing on early (11% vs. 14%) and late mortality (5.8%/year vs. 5.0%/year). Re-evaluation in 50 patients showed that Kay's bicuspidalization and de Vega's annular plication gave similar and good late result in about 70% of the cases. The risk of over-correction was low in that only 1/30 cardiac catheterization revealed signs of mild tricuspid stenosis. Recurrent or residual tricuspid incompetence is probably related to the severity of the individual cases. Some of these failures were evident already on the patient's discharge from hospital but, unfortunately, not predictable from the pre- or intra-operative evaluations.

Adolescent↗
PubMed1980

Central haemodynamics at rest and during exercise before and after combined aortic and mitral valve replacement with the Björk-Shiley tilting disc valve prosthesis.

Pre- and postoperative haemodynamics were compared in 36 patients with combined aortic and mitral valvular disease. These patients suffered from markedly restricted cardiac function in terms of cardiomegaly, low physical working capacity, hypokinetic central circulation and pulmonary hypertension. Valve replacement was performed with the Björk-Shiley Delrin disc (10) and pyrolytic carbon disc (26) prostheses and followed by subjective improvement in the majority of patients. Heart volume decreased and working capacity increased in average significantly, but were not restored to normal. The main response to surgery was a shift towards a normokinetic circulation, although many patients remained hypokinetic. There was also regression of pulmonary hypertension as a result of reduced left atrial pressure and pulmonary vascular resistance. In spite of a significant decrease in left atrial mean pressure, it remained elevated with prominent v-waves in many patients, particularly during exercise. Marked v-waves in the right atrial pressure curves were also noted in one third of the patients. Only one patient, however, suffered from clinically manifested tricuspid incompetence. This study shows the benefits of combined aortic and mitral valve replacement, even in patients with longterm haemodynamic burden on the myocardium. Although the central haemodynamics were almost normalized at rest, abnormal responses persisted during exercise.

Adult↗
PubMed1978

Coarctation of the aorta. The world's longest follow-up.

A 32-year follow-up of the first coarctations of the aorta ever operated upon in the world has shown a systolic blood pressure below 155 mmHg in 12 of 18 patients and a diastolic blood pressure below 95 mm Hg in 15 of 18 patients. No gradient over the anastomosis was noted in 13 of 18 patients when measured by a cuff and in 5 of 12 patients when measured by catheterization. If the diameter of the anastomosis was 75% of that of that of the aortic arch, only a very small or no resting gradient was found. If there was no gradient at rest, there was usually only an insignificant or no gradient during exercise. A small gradient at rest was always higher during exercise, depending on the degree of work load, length of narrowed segment and aneurysm at the suture line. There was an incidence of 44% aortic valvular disease and of 20% degenerative changes in caput femoris. The anastomosis had grown with the patient.

Adolescent↗
PubMed1978

Clinical evaluation of the Björk-Shiley tilting disc valve in the tricuspid position. Early and late results in 10 isolated and 51 combined cases.

Tricuspid valve replacement with the Björk-Shiley tilting disc valve was performed in 61 consecutive patients with either organic disease causing valve malfunction or functional regurgitation of severe degree. The early mortality rate was 21% (13/61) for the entire series. It was 10% (1/10) for tricuspid valve replacement alone, 27% (9/33) for mitral and tricuspid valve replacement, and 18% (3/17) for triple valve replacement. Age over 60 years, functional capacity group IV (N.Y.H.A.) and heart volume over 900 ml/m2 BSA were factors associated with a high operative mortality. There were 3 late deaths, 42, 42 and 45 months, respectively, after surgery, due to arrhythmia (2) and anticoagulant complications (1). The Björk-Shiley prosthesis has functioned well and with satisfactory clinical improvement in the majority of the 48 long-term survivors, for an average period of 2.8 years. There were, however, 3 cases of prosthetic valve failure due to thrombotic obstruction following isolated tricuspid replacement because of Ebstein's anomaly (2) and traumatic tricuspid valvular incompetence (1). Reoperation with insertion of a new Björk-Shiley prosthesis involved no mortality. One patient, however, had a recurrent prosthetic thrombosis which was successfully treated with streptokinase. Only one patient in the series, who underwent triple valve replacement, suffered from systemic embolism, an incidence of 0.7 per 100 patient years. There were no episodes of pulmonary embolism or infective endocarditis.

Adolescent↗