Plasma thromboxane B2 as an early marker of acute graft rejection after heart transplantation: preliminary report.

Six patients undergoing heart transplantation were followed up by serial endomyocardial biopsies to detect signs of graft rejection and the plasma level of thromboxane B2 was measured at the same time. During the operative procedure and concomitant with histologic signs of acute graft rejection, the plasma level of thromboxane B2 significantly increased. After immunosuppressive treatment with steroids and either antithymocyte globulin or monoclonal antibody, regression of the histologic signs of rejection and a significant fall in the level of thromboxane B2 were documented. We conclude that the plasma level of thromboxane B2 may be useful as an early marker of acute graft rejection after heart transplantation.

Lower limb embolectomy in old age.

The results of embolectomy in 56 patients, aged 80 years or more, with acute embolic lower limb ischemia are presented. An overall mortality rate of 32% is found. In patients with a simultaneous myocardial infarction the mortality rate was 100%. Of the surviving 38 patients 29 avoided amputation and were discharged with unchanged social and functional status. Bases on the present findings it is concluded, that embolectomy should always be tried, especially since it has been shown, that an unsuccessful embolectomy does not lead to an increased mortality if an eventual subsequent amputation has to be carried out.

Evaluation of patients with thoracic aortic dissection by intraarterial digital subtraction angiography.

In 17 patients (mean age 60 years) a thoracic aortic dissection could be revealed by intraarterial digital subtraction angiography with exact delineatin of the proximal and distal extent. Furthermore a visualisation of the true and false lumen and hereby especially the blood flow and its direction in the false lumen could be made. The disclosure of the intimal flap could be seen in patients with flow in both channels, separating the true and the false lumen. In 4 patients the entry could be seen sharply as a hole, but not corresponding to the proximal extent. In 11 patients the entry was seen over a longer area and in 2 patients neither entry nor reentry could be seen. The most distal part of the intimal flap might correspond to the reentry. One anonymous artery, five renal arteries and one coeliac trunc were involved by the dissection. The exact anatomical and pathophysiological nature of the dissection made it possible to decide whether or not the patients should be operated upon and if so, what kind of operation should be chosen.

[An automatic implantable heart rhythm converter and defibrillator]. / Automatisk implanterbar kardioverter og defibrillator.

Ventricular tachycardia and fibrillation can be converted to sinus rhythm by DC-countershock. An implantable cardioverter defribillator (ICD) has been developed. The apparatus monitors the heart rhythm continuously, detects ventricular tachycardia and ventricular fibrillation and delivers one or more DC-counter shocks a few seconds after the dysrhythm has started. This always ensures rapid treatment, even if the patients is outside hospital. Two case histories are presented and the ICD treatment is discussed.

[Thromboendarterectomy of chronic thromboembolic pulmonary hypertension]. / Trombendarterektomi af kronisk tromboembolisk pulmonal hypertension.

Chronic thromboembolic pulmonary hypertension has a five year survival rate of less than 10% in patients with a systolic pulmonary artery pressure of 50 mmHg with no convincing effect of medical treatment. The operative mortality from pulmonary thrombendarterectomy in specialised centres has been reduced to 9%, suggesting this treatment as being an option. The results from thrombendarterectomy of two Danish patients are reported. The first patient, a 34 year-old woman was operated at the centre in San Diego with the assistance of a Danish thoracic surgeon. The second, a 60 year-old man was operated at our institution by this surgeon. Following removal of sufficient amount of embolic masses and intimal tissue, the patients were discharged from hospital with a substantial improvement in their clinical status and near normalisation of pulmonary artery pressure, which remained at the latest follow-up (3 to 22 months).

[Chronic thromboembolic pulmonary hypertension]. / Kronisk tromboembolisk pulmonal hypertension.

Acute pulmonary hypertension has a high mortality at the onset. Patients surviving the first phase will usually recanalize the pulmonary arteries through intrinsic thrombolytic mechanisms and medical treatment. However, in some cases there is insufficient resolution of the emboli with subsequent thrombotic and fibrotic reorganization, leading to a worsening of the pulmonary obstruction. In the open pulmonary arteries the disease may lead to hypertrophy of the media and intimal proliferation, thus leading to a further increase in the pulmonary vascular resistance. This again leads to hypertrophy of the right ventricle and ultimately to right-sided heart failure. Untreated, chronic thromboembolic pulmonary hypertension has a five-year mortality approaching 100%, but extensive pulmonary thrombendarterectomy using extracorporeal circulation and deep hypothermia has been shown to lower the pulmonary vascular resistance and thereby improve the prognosis significantly. Operative treatment can now be offered in Denmark, and the purpose of this review is to draw attention to the disease, its symptoms, diagnosis and the surgical treatment.

[Atrial fibrillation after coronary artery bypass surgery. The significance of preoperative vagus modulation and ectopic atrial activity]. / Atreiflimren efter koronar bypass-kirurgi. Betydningen af proeoperativ vagusmodulation og ektopisk atrieaktivitet.

To investigate the impact of pre-operative autonomic balance and atrial ectopic activity on the risk of atrial fibrillation or flutter after aorto-coronary artery bypass surgery 24-hour Holter monitoring was analyzed in 102 patients before coronary artery bypass grafting. Index for vagal tone was calculated as % successive RR-interval differences > 6%. Twenty-nine (28%) of the 102 patients developed atrial fibrillation or flutter. Independent predictors (90% confidence interval) of postoperative atrial fibrillation or flutter were identified by logistic regression analysis: the independent predictors were older age, relative risk 1.07/year (1.02-1.12), vagal index < 10%, relative risk 4.50 (1.40-14.5), > or= 10 ectopic supraventricular beats/24 hour, relative risk 3.03 (1.05-8.72), and one or more event of non-sustained supraventricular tachycardia, relative risk 3.02 (1.11-8.22). Thus, age of the patient, attenuated preoperative cardiac vagal modulation, ectopic supraventricular beats, and paroxysmal non-sustained supraventricular tachycardia are independent risk factors for the development of atrial fibrillation or flutter after coronary artery bypass surgery.

[Diagnosis of suspected thoracic aortic dissection. Focused on transesophageal echocardiography]. / Diagnostik ved mistaenkt torakal aortadissektion. Fokus på transøsofageal ekkokardiografi.

Over a five-year period (1990-1994), 72 consecutive patients were referred to transoesophageal echocardiography (TEE) on suspicion of thoracic aortic dissection. TEE was performed as the only or last investigation in 42 patients (58%). In 44 patients one or more other investigations were carried out before final clinical decision making: aortography (n = 30), X-ray computer tomography (CT, n = 18), and magnetic resonance imaging (MRI, n = 12). The final diagnosis was based on the combination of clinical information, the available examination results, and findings at surgery or autopsy; 31 of the patients were diagnosed as having aortic dissection. One patient with aortic dissection died during TEE while none of the other patients suffered major complications. The sensitivity (demonstration of dissection including correct classification in type A or B) was 81%, 80%, 45%, and 83% for TEE, aortography. CT, and MRI, respectively. The specificities were 88%, 93%, 71%, and 100%, respectively. Dissection of the thoracic aorta is a life-threatening condition demanding prompt and accurate diagnosis. None of the four techniques employed in the present study is ideal. Although TEE is adequate for immediate bedside examination our results show that more time-consuming and resource demanding investigations are sometimes required. Proper training and improved equipment may, however, increase the usefulness of TEE in patients with suspected aortic dissection.

Inadequately reduced acid secretion after vagotomy for duodenal ulcer. A follow-up study three to nine years after surgery.

In a study of 545 patients who underwent vagotomies for repair of duodenal ulcers, 62 patients (11%) were found to have inadequately reduced pentapeptide and/or insulin-stimulated acid secretions three months after operation. The ulcers recurred in 14 patients within three to nine years (mean: four years) (23%, 95% confidence limits: 13-35). Postoperative acid production and acid reduction were equal in patients with and without ulcer recurrence. The patients who did not develop recurrent ulcers had significantly lower preoperative pentapeptide peak acid outputs and significantly shorter preoperative histories of ulcers than patients whose ulcers recurred.

Intraaortic balloon pumping in the treatment of low cardiac output following open heart surgery--immediate results and long-term prognosis.

From 1979 through 1986, 90 patients required intraaortic balloon pumping (IABP) due to low cardiac output complicating open heart surgery. Preoperatively, functional class III or IV was present in 92%; in patients with coronary artery disease (n = 54), three-vessel or left main disease was found in 72%; patients with valvular disease (n = 37) generally had multiple surgical procedures or valve re-replacement performed. Intra-IABP mortality was 49% (n = 44) and 30-day mortality 61% (n = 55). The latter figure decreased from 75% in 1979-81 to 53% in 1985-86. Cumulative 5-year survival was 22%. Logistic regression analysis identified as independent predictors of 30 day mortality the necessity for adjuvant treatment with the more powerful "pressure drugs" isoprenaline/noradrenaline, number of DC-defibrillations, functional classes III-IV, and chronic left ventricular failure. Different combinations of these risk factors identified different patient groups with 30-day mortalities ranging from 100% to 0%. The risk factors reflected both acute cardiac failure probably due to severe ischemia and chronic failure due to advanced primary disease. Taking the high-risk composition of the material into account, a 5-year survival of 22% cannot be regarded as discouraging. Continued employment of IABP treatment in open heart surgery, using an aggressive approach coupled with individualized inotropic support, seems justified.

Premature atrial beat eliciting atrial fibrillation after coronary artery bypass grafting.

Of patients undergoing coronary artery bypass grafting 30% develop atrial fibrillation (AF) or flutter. To determine if AF is initiated from the right or left atrium, atrial electrograms were continuously recorded in patients undergoing this procedure. In addition, to study whether the prematurity index of premature atrial contractions (PACs) eliciting AF differs from PACs not provoking AF, the distribution of prematurity indices was evaluated from R-R interval analysis. The right and left atrial recording electrodes were first activated by the ectopic beat provoking AF in six and eight patients, respectively. The prematurity index of the PAC eliciting AF was located in the middle (in half of the patients) or to the left of the median distribution of prematurity indices. The variability in activation of the atrial electrodes suggests that the PAC provoking AF can have its origin in the right, the septal, or the left region of the atrium. The initiation of AF depends on the prematurity index of the PAC.

Low vagal tone and supraventricular ectopic activity predict atrial fibrillation and flutter after coronary artery bypass grafting.

To investigate the impact of pre-operative autonomic balance and atrial ectopic activity on the risk of atrial fibrillation or flutter after aorto-coronary artery bypass surgery 24-h Holter monitoring was analysed in 102 patients before coronary artery bypass grafting. Index for vagal tone was calculated as % successive RR interval differences > 6%. Twenty-nine (28%) of the 102 patients developed atrial fibrillation or flutter. Independent predictors (90% confidence interval) of postoperative atrial fibrillation or flutter were identified by logistic regression analysis: the independent predictors were older age, relative risk 1.07.year-1 (1.02-1.12), vagal index < 10%, relative risk 4.50 (1.40-14.5), > or = 10 ectopic supraventricular beats . 24 h-1, relative risk 3.03 (1.05-8.72), and one or more events of non-sustained supraventricular tachycardia, relative risk 3.02 (1.11-8.22). Thus, age of the patient, attenuated pre-operative cardiac vagal modulation, ectopic supraventricular beats, and paroxysmal non-sustained supraventricular tachycardia are independent risk factors for the development of atrial fibrillation or flutter after coronary artery bypass surgery.