Hemodynamic evaluation by Doppler echocardiography of small (less than or equal to 21 mm) prostheses and bioprostheses in the aortic valve position.

To assess resting hemodynamics of an unselected group of patients with prostheses or bioprostheses sized less than or equal to 21 mm implanted into the aortic valve position during a 7-year period, 46 of 50 eligible patients were examined by Doppler echocardiography. The valves were Carpentier-Edwards (CE) supraannular 21 mm (n = 8), Medtronic-Hall (MH) 20 mm (n = 8) and 21 mm (n = 21), and the rest (n = 9) were other valves with only 1 to 3 patients in each group. Gradients, valve areas and dimensionless obstruction indexes (ratio of subvalvular/valvular velocities and velocity time integrals) were compared. By analysis of variance, gradients did not differ significantly between the CE supraannular 21 mm, the MH 20 and 21 mm prostheses (peak/mean 25 +/- 8/14 +/- 5, 31 +/- 13/16 +/- 6 and 25 +/- 10/13 +/- 5 mm Hg; p = not significant). Only 2 patients had a mean gradient greater than 25 mm Hg. The valve area was slightly larger for the MH 21 mm group compared with the CE supraannular 21 mm group (1.34 +/- 0.15 vs 1.16 +/- 0.14 cm2, p less than 0.05). The dimensionless obstruction indexes did not differ (CE supraannular 21 mm 0.36 +/- 0.07/0.40 +/- 0.07 (velocities/velocity time integrals), MH 20 mm 0.40 +/- 0.12/0.47 +/- 0.12, MH 21 mm 0.38 +/- 0.05/0.44 +/- 0.06; p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombotic disc impediment in a Medtronic-Hall aortic valve prosthesis diagnosed by Doppler echocardiography followed by successful reoperation.

A case with impeded disc movement caused by thrombus formation in a Medtronic-Hall aortic valve prosthesis is reported. A correct diagnosis, including both mechanism and severity of the prosthesis failure, was established by Doppler echocardiography. The patient was promptly referred for surgery without invasive or other supplementary investigations.

Effects of thoracic epidural analgesia on pulmonary function after coronary artery bypass surgery.

OBJECTIVE: A substantial reduction in lung volumes and pulmonary function follows cardiac surgery. Pain may prevent effective breathing and coughing, and as thoracic epidural analgesia may reduce postoperative pain, we investigated the effect of epidural analgesia on pulmonary function. METHODS: Fifty-four male patients, under 65 years and with an ejection fraction of more than 0.5, were randomized into two groups: a control group receiving high-dose fentanyl anaesthesia and an epidural group receiving low-dose fentanyl anaesthesia + thoracic epidural analgesia. Time to awakening and time to extubation were recorded. Further, spirometric data, arterial oxygenation, pulmonary shunt, haemodynamics, use of vasoactive drugs and fluid balance were followed for up to 6 days postoperatively. RESULTS: Patients with low-dose fentanyl and epidural analgesia awoke (1.6 vs 3.6 h) and were extubated (5.4 vs 10.8 h) significantly earlier than control group patients. A 50-70% reduction in forced vital capacity, forced expiratory volume in 1 s (FEV1.0) and peak expiratory flow rate (PEFR) was seen after surgery, but higher FEV1.0 and PEFR on days 2 and 3 were seen in the epidural group than in the control group. Pulmonary shunt and alveolo-arterial oxygen difference increased similarly in both groups, whereas oxygen delivery and mixed venous oxygen saturation were higher in the epidural group. Epidural analgesia gave better control of the postoperative hyperdynamic circulation. CONCLUSIONS: Thoracic epidural analgesia yields a slight, but significant, improvement in pulmonary function, most likely due to a more profound postoperative analgesia.

The relationship between preoperative coronary angiography and clinical outcome of aortocoronary bypass surgery.

Two hundred and fifty preoperative coronary cineangiograms were reviewed. All observed stenoses were evaluated with regard to location, severity and suitability for bypass grafting. The angiographic prediction for a successful surgical result was classified as "doubtful", "acceptable", "good" and "very good". This was compared with the clinical result following surgery. All patients were operated on during the period March 1983 and November 1985. The mean observation time with regard to subjective improvement was 2.7 years (range 1.6-4.3). In the group "doubtful", containing 7 patients, 6 became free of symptoms or much improved, whereas one patient was unchanged. This was better than expected. In the group which was estimated to be "very good", including altogether 54 patients, approximately the same degree of improvement was achieved as in the other groups. An exercise test was performed 4.9 years (range 3.6-6.7) postoperatively. The distribution of positive exercise stress tests indicating remaining coronary ischemia, was almost equally divided in the four groups, except for the group "very good" where the share of positive tests was less. It is concluded that predicting the result of the operation from preoperative angiograms may be difficult, and unreliable in the groups where the results are predicted to be "acceptable" or "doubtful".

Aortic valve replacement. A randomized study comparing the Björk-Shiley and Lillehei-Kaster disc valves. Peroperative haemodynamic evaluation and early results.

Three hundred patients were selected at random in order to compare the Björk-Shiley and the Lillehei-Kaster valves in the aortic position. Peroperative haemodynamic evaluations were carried out in 106 cases. The effective orifice area of the valves and the effective area index were calculated. The results indicate that the Björk-Shiley valves utilize the available space in the aortic root about 12% better than the Lillehei-Kaster valves. There were 11 hospital deaths, but none of them were valve related.

Aortic valve replacement. A randomized study comparing the Björk-Shiley and Lillehei-Kaster disc valves. Long-term results.

Three hundred patients were selected at random in order to compare the Björk-Shiley (B-S) and Lillehei-Kaster (L-K) valves in the aortic position. The mean follow-up time was 4 3/4 years (range 3 1/4-7 years). There were 15 late deaths in the B-S group and 23 in the L-K group. The incidence of sudden and unexpected deaths was much higher in the L-K than in the B-S group (10:1). The 7-year actuarial survival rate was 82% in the B-S and 76% in the L-K group. In both groups the survival rate was higher in patients with large valves than in those with small valves; in the L-K group this difference was significant (p less than 0.02). The overall thrombo-embolic rate was 3.2 per 100 patient years in the B-S and 2.8 in the L-K group. Valve thrombosis occurred in 3 patients with B-S valves and in 4 with L-K vales. One of the L-K valves was thrombosed early after operation due to faulty suture technique. Of the long-term survivors of working age 80% in the B-S and 70% in the L-K group returned to work. There was a close correlation between functional capacity (NYHA) and the employment rate.

Aortic valve replacement. A randomized study comparing Björk-Shiley and Lillehei-Kaster disc valves. Haematological evaluation.

In this study, 79 randomized patients with either Björk-Shiley (B-S) or Lillehei-Kaster (L-K) aortic disc valves were re-admitted two years after operation for clinical, haemodynamic and haematological evaluation. This paper deals in particular with the haematological results. Cine-aortography was carried out in 76 patients and left ventricular catheterization via the transseptal approach was performed in 43 patients. Haemoglobin concentration, erythrocyte count, platlet count, reticulocyte count, plasma haemoglobin concentration, serum bilirubin, serum iron, serum haptoglobin and serum lactate dehydrogenase were studied in the patients. Postoperatively all patients had normal haemoglobin and erythrocyte count. Haptoglobin was absent or reduced in 43% of patients with B-S valves and in 65% of those with L-K valves. Serum lactate dehydrogenase activity (LDH) was abnormally elevated in 26% of patients in the B-S group and in 65% of those in the L-K group. Mean LDH was significantly higher in the L-K group compared with the B-S group (p less than 0.01). A highly significant linear correlation could be demonstrated between mean systolic pressure difference across the valve (delta pm) and LDH (p less than 0.001). This finding helps to explain why the L-K valves provoke more erythrocyte destruction than the B-S valves, since delta pm proved to be significantly higher in the L-K group. LDH was not significantly increased in 6 patients in whom a paravalvular leakage was demonstrated.

Post-infarction left ventricle to right atrium fistula diagnosed by transthoracic Doppler echocardiography.

This is a report of a 63-year-old man who in the course of an inferior wall myocardial infarction developed a left ventricular aneurysm with communication to the right atrium and a haemodynamically significant intracardiac shunt. The unusual complication of a myocardial infarction was correctly diagnosed by transthoracic Doppler echocardiography, and later a successful surgical repair was done.

Procaine is effective for minimizing postischemic ventricular fibrillation in cardiac surgery.

Procaine hydrochloride was added to cardioplegia and studied for its efficacy in stabilizing the postischemic rhythm after aortic declamping in cardiac surgery. Fifty-six patients scheduled for coronary artery bypass grafting (CABG), were included in a randomized, double-blind study. The patients were anesthetized with isoflurane, low-dose fentanyl, diazepam, and pancuronium. In the study group (28 patients), St. Thomas' Hospital cardioplegic solution II (Plegisol) was prepared with 1 mM procaine. The control group (28 patients) was given the same cardioplegia with saline. Ventricular fibrillation (VF) occurring after declamping was treated with direct current (DC) shock (8-12-12-20 J). There were no significant differences with regard to demographic properties or anesthesiologic and surgical treatment. Two patients (7%) in the procaine group required DC shock for VF, compared to 28 (100%) in the control group (P < 0.001). The amount of lidocaine (mean +/- SEM) given for resistant dysrhythmias was 3.6 mg +/- 3.6 in the procaine group compared to 35.7 mg +/- 9.2 in the control group (P < 0.002). One patient in each group required temporary pacing. The number of synchronized DC shocks for conversion of atrial fibrillation was lower in the procaine group (P < 0.05). The enzyme release the first day after surgery was lower in the procaine group (P < 0.05). Procaine (1 mM) in cardioplegia stabilizes the postischemic rhythm in CABG surgery in humans without any observed adverse effects.

Aortic valve replacement. A randomized study comparing the Björk-Shiley and Lillehei-Kaster disc valves. Transvalvular regurgitation and occurrence of paravalvular fistulas.

Three hundred patients were selected at random in order to compare the Björk-Shiley (B-S) and the Lillehei-Kaster (L-K) valves in the aortic position. The transvalvular regurgitation was evaluated by peroperative flow recordings in 97 cases. The leakage was found to be 7.6% and 7.5% of forward flow in the B-S and L-K valves, respectively. The regurgitant flow pattern, however, was different in the two groups, as leakage on closure was significantly larger in the L-K valves, and the leakage after closure of the disc was significantly larger in the B-S valves. Follow-up cine-aortography was carried out two years postoperatively in 91 patients. The contrast leakage through the valves was found to be minimal (Grade I) in about 90% in both groups. In one patient with a L-K valve no leakage could be demonstrated. In the remaining patients the leakage was moderate (Grade II). Paravalvular fistulas were demonstrated in three patients from each group. In one patient the paravalvular regurgitation was marked (Grade III), in the others moderate (Grade II). Cine-aortography was also carried out in a further 9 patients, in whom a paravalvular leakage was suspected according to clinical follow-up examinations. In four of these patients a paravalvular regurgitation was demonstrated. The leakage was moderate in two patients and severe (Grade IV) in another two, who were successfully re-operated on.

The effect of positive end expiratory pressure after three types of open heart surgery.

It has previously been shown that patients who have undergone mitral valve replacement (MVR) tolerate a positive end expiratory pressure (PEEP) of 1.0 kPa better than patients who have had aortic valve replacement (AVR). the difference was explained by the fact that the mitral patients had pre-existing pulmonary vascular disease. In the present study the effect of PEEP up to 2.0 kPa is investigated in three types of operations: aortocoronary bypass graft (ACBG), mitral valve replacement, and aortic valve replacement; there were five patients in each group. We found that our mitral patients tolerated PEEP better than the two other groups, and that tolerance was not correlated to a higher pulmonary vascular resistance, but rather to a higher level of pulmonary capillary wedge pressure. The influence of PEEP varies in different types of patients and the effect is still difficult to predict.

[Cardiogenic cause of cerebral embolism]. / Kardiogen årsak til cerebral emboli.

Cerebral insults of cardiac origin are often of great functional importance. The most common cause is atrial fibrillation. Other sources of cerebral embolies, even if rare, such as cardiac tumors, must not be ignored. Many of these patients present neurologic symptoms. The diagnosis is established on ecco-cardiography. Surgical management is the treatment of choice. We discuss a young patient with multiple cerebral insults and a papillary cardiac tumor.

Comparison of intraoperative flow measurements and haemodynamic findings at follow-up in patients with different aortic disc valve prostheses.

Intraoperative as well as postoperative assessment of effective orifice area, determined by relating flow through a prosthetic heart valve to the pressure gradient measured across the valve, provides a data base for comparison of different types of cardiac prostheses. As a measure of valve performance, we have used the derivation of both the effective area according to the Aaslid formula measured intraoperatively and to the Gorlin formula measured at a re-catheterization study. We also established the parameter 'effective index area', Ia or Ii. Ia is defined as the ratio between the effective orifice area and the annulus orifice area, and Ii as the ratio between the effective orifice area and the internal orifice area of the valve housing. The patients included in the study had either Lillehei-Kaster, Björk-Shiley or Hall-Kaster aortic valve prostheses inserted. In most of the Lillehei-Kaster prostheses, Ia varied around 0.27 and Ii around 0.56, while the corresponding values in the Björk-Shiley prostheses were 0.35 and 0.56, increasing to around 0.50 and 0.75 respectively in the Hall-Kaster prostheses.

Two-dimensional echocardiography for prediction of aortic valve prosthesis size. A comparative study of Medtronic-Hall and Carpentier-Edwards supra-annular valves.

To assess the value of two-dimensional echocardiography (2D ECHO) for predicting prosthetic aortic valve size, the diameter of the aortic annulus was measured before implantation of a Medtronic-Hall valve in 24 patients and a Carpentier-Edwards supra-annular valve in 34. In the Medtronic-Hall group, the average prosthesis size was similar to the average annulus diameter, i.e. 23.2 +/- 2.1 vs 23.0 +/- 3.4 mm (NS), 95% confidence interval for the difference -1.0-0.7 mm. In the Carpentier-Edwards group the corresponding figures were 23.5 +/- 2.1 and 22.0 +/- 2.3 mm (p < 0.001), with 95% confidence interval 0.9-2.0 mm. Correlation between annulus diameter indicated by preoperative 2D ECHO and prosthesis size was stronger in the Medtronic-Hall (r = 0.88, p < 0.001) than in the Carpentier-Edwards group (r = 0.73, p < 0.001). The authors conclude that prosthetic aortic valve size may be accurately predicted by 2D ECHO, with Medtronic-Hall valve size similar to, and Carpentier-Edwards prostheses on average 1-2 mm larger than the 2D ECHO-estimated annulus diameter.

Exercise hemodynamics in small (< or = 21 mm) aortic valve prostheses assessed by Doppler echocardiography.

Exercise Doppler echocardiography was used to assess hemodynamics in 25 patients with a < or = 21 mm aortic valve prosthesis (14 with a Medtronic-Hall 21 mm valve, three with a Medtronic-Hall 20 mm valve, three with a Sorin 21 mm valve, one with a Duromedics 21 mm valve, and four with a Carpentier-Edwards 21 mm valve). A symptom-limited upright bicycle exercise test was performed, and Doppler gradients were recorded during exercise. Gradients increased with exercise from 30 +/- 8/16 +/- 4 mm Hg (peak/mean) at rest to 46 +/- 12/24 +/- 7 mm Hg during exercise; both p < 0.001. Mean exercise gradient exceeded 30 mm Hg in five patients, and the highest mean gradient recorded was 37 mm Hg. Within the group of mechanical valves, gradients at exercise were similar for different types of valves. A linear relationship was found between gradients at rest and during exercise (peak r = 0.75, mean r = 0.77; both p < 0.001). Additional findings were midventricular velocities exceeding 1.5 m/sec in late systole in 10 patients (40%) and intraventricular flow (> or = 0.2 m/sec) toward the apex during isovolumic relaxation in 11 patients (44%). The patients with these velocity patterns had significantly smaller left ventricular cavities (end-diastolic diameter 39.8 +/- 4.8 vs 46.5 +/- 4.2 mm, p < 0.01; end-systolic diameter 24.2 +/- 3.0 vs 28.5 +/- 4.5 mm, p = 0.013).(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic valve replacement. A randomized study comparing the Björk-Shiley and Lillehei-Kaster disc valves. Late haemodynamics related to clinical results.

In this study, 78 randomized patients with either Björk-Shiley (B-S) or Lillehei-Kaster (L-K) aortic disc valve prostheses were re-admitted for clinical and haemodynamic evaluation. The patients were selected that those with narrow aortic roots were over-represented. Cine-aortography was carried out in 75 patients and left ventricular catheterisation via the transseptal approach was performed in 42. The clinical improvement was striking, although the number of patients still incapacitated was relatively large in patients with the small L-K valves (Nos. 14 & 16). Peak-to-peak and mean systolic pressure differences across the valves were significantly lower in the B-S than in the L-K valves, particularly when the small valve sizes were compared. Left ventricular end-diastolic pressure (LVEDP), which was elevated in most patients before operation, decreased significantly to normal levels in the B-S group. In the L-K group, LVEDP did not decrease significantly and was on the average still above the normal level after operation, probably due to the relatively large pressure gradients. The study indicates that the L-K valves Nos. 14 & 16 in particular represents a resistance to flow that is too large to be acceptable in clinical practice.

"In situ" evaluation of the aortic pivoting disc valve prosthesis.

An index of the "in situ" forward flow characteristics of an aortic valve prosthesis is suggested. The effective area index, Ia, is defined as the ratio between the effective orifice area, Aeff, and the area occupied by the valve in the aortic root. Aeff is calculated from a hydraulic formula using peroperative measurements of instantaneous ascending aortic flow, Fao, and the pressure gradient, deltaP. Ia was found to be 0.29 +/- 0.33 (S.D.) for Lillehei-Kaster valves and 0.32 +/- 0.059 (S.D.) for Björk-Shiley valves. The variations in valve performance among the Björk-Shiley valves may partly be due to differences in valve orientation in the aortic root. Attention should therefore be given to the choice of the opening direction of the disc in order to optimize valve performance in the patient.

[Surgical treatment of angina pectoris in elderly patients]. / Kirurgisk behandling av angina pectoris hos eldre.

Twenty-eight patients, age 65 years or more, received aortocoronary bypass surgery during the period 1983-85. There was one early death. There were no serious complications connected with the operation, but increased risk of complications is to be expected with higher age. The postoperative stay in hospital is somewhat longer in the elderly. At follow-up, after 19-52 months, 14 patients were free of symptoms, seven were much improved and four were improved.

[Surgical treatment of carcinoid bronchial tumor]. / Kirurgisk behandling av karsinoid bronkialtumor.

During the period 1977-95, 20 patients underwent surgery for carcinoid tumour in the bronchus at the University Hospital of Trondheim (n = 16) and Innherred County Hospital (n = 4). All the tumours were typical carcinoid tumours. Median age of the patients was 41 years (range 16-78 years). The observation period averaged 7.5 years (0.5-18 years). The most common symptoms were cough, dyspnoea, wheezing and pneumonia. One patient had carcinoid syndrome. Chest X-ray were negative in three of the patients. Bronchoscopy was carried out in all the patients. Biopsies were taken in ten of them, and the diagnosis was conclusive in five cases. Lateral thoracotomy was performed in all the patients. The surgical procedures were lobectomy (15), segmental/wedge resection (3), bronchotomy with tumour resection (1) and sleeve resection (1). 19 patients were still alive at the time of follow-up, with no tumour recurrence. One patient died from cerebral stroke eight years after surgery. Good long-term results were found, and the study supports the use of limited lung resection or bronchoplasty operations to treat carcinoid tumour in the bronchus if the primary tumour is localised and there are no metastases.

Surgical treatment of aneurysms of the descending thoracic aorta.

Six patients were operated on for aneurysm of the descending thoracic aorta in 1983-1985 by use of simple cross-clamping and interposition of a Dacron tube graft without extracorporeal circulation. The aneurysm had ruptured in three cases. The patients' mean age was 69 years. Anesthesia and muscle relaxation were obtained by drugs with only minor myocardial depressant action. There was no postoperative mortality or morbidity. Five of the patients have been followed up for at least a year. Careful pharmacologic control of the blood pressure is essential during such surgery. Despite the smallness of the series, it indicates that simple cross-clamping and Dacron graft interposition can be used for treatment of aneurysm of the descending thoracic aorta.