Surendra K. Naik

Postinfarction Ventricular Free Wall Rupture: Strategies for Diagnosis and Treatment

Ventricular free wall rupture is a recognized complication of myocardial infarction. In recent years, the widespread availability of echocardiography has enabled prompt antemortem diagnosis. Consequently, an avenue for lifesaving surgical intervention has emerged for this hitherto fatal condition. We review the pathology and discuss strategies for diagnosis, resuscitation, and definitive surgical intervention. We illustrate this review using our experience with a patient whose condition was diagnosed by transthoracic echocardiography and who successfully underwent emergency operation.

The time course of pulmonary transfer factor changes following heart transplantation.

OBJECTIVE The pulmonary transfer factor for carbon monoxide (TLCO) has been reported to decline following heart transplantation, but the time course of this decline is not well documented. The aim of this study was to define the longitudinal changes in TLCO after heart transplantation. METHODS Single breath TLCO, lung volumes and expiratory flow rates were prospectively measured in 57 patients (mean age 49 years, range 19-61) before and at least once after heart transplantation. Thirty seven of the 57 patients had four post-transplant assessment which were performed at 6 weeks, 3, 6 and 12 months in 26 patients and at 12, 18, 24 and 36 months in 11 patients. Results were compared with data from 28 normal subjects (mean age 40 years, range 19-61). RESULTS Before transplantation there was a mild impairment of lung volumes and expiratory flow rates. At 6 weeks after transplantation, there was a further reduction in the forced expiratory volume in one second, forced vital capacity, residual volume and total lung capacity, but all of these increased in the subsequent measurements to exceed their pre-transplant values at about 1 year after transplantation. Haemoglobin-corrected TLCO was also reduced before transplantation compared to normal controls (74.3% and 98.6% of predicted respectively, P < 0.001). Although TLCO per unit alveolar volume (KCO) was relatively preserved in heart transplant candidates, it was still significantly lower than that of normal controls (92.6% and 105.3% of predicted respectively, P < 0.05). After transplantation, mean haemoglobin-corrected TLCO and KCO declined by 12% and 20% of predicted respectively) with the majority of patients having reductions greater than 10% of predicted. The decline in TLCO and KCO was evident at 6 weeks after transplantation with no further changes in the subsequent measurements. CONCLUSIONS TLCO is reduced in heart transplant candidates and declines further after heart transplantation despite improvement in lung volumes and airway function. The early and non-progressive nature of TLCO decline suggests an aetiology exerting its effect on TLCO within the first 6 weeks after transplantation.

Mechanisms of pulmonary transfer factor decline following heart transplantation

OBJECTIVE Although the decline in the pulmonary transfer factor (TL(CO)) following heart transplantation is well documented, the causes and mechanisms of this decline remain unknown. The aim of this study was to determine the relative contribution of each of TL(CO) components (the diffusing capacity of the alveolar-capillary membrane (D(M)), the pulmonary capillary blood volume (V(C)) and haemoglobin concentration) to TL(CO) reduction in heart transplant recipients. METHODS TL(CO) and its components were measured in 75 heart transplant recipients (mean age 48 years, range 19-61) between 6 weeks and 36 months after transplantation using the Roughton and Forster method and the single-breath technique. Results were compared with data from 38 heart transplant candidates (mean age 51 years, range 34-61) and 26 normal subjects (mean age 47 years, range 27-62). RESULTS The mean percentage predicted TL(CO) was reduced in recipients compared to candidates (56.9 and 69.9%, respectively, P<0. 001) and both were lower than normal controls (97.7%, P<0.001). The mean percent predicted V(C) was also reduced in recipients compared to candidates (52.8% vs. 80.2 (4.2)%, P<0.001) which was also lower than normal subjects (102%, P<0.001). D(M) was equally reduced in recipients and candidates (77.7 and 81.4%, respectively, P=0.48) compared to normal subjects (100.0%, P<0.001). Correction for haemoglobin concentration increased TL(CO) in recipients to 63.5% (P<0.001), but it remained lower than haemoglobin-corrected TL(CO) in candidates (71.1%, P<0.001). In recipients, the intra-capillary resistance (1/thetaV(C)) formed 60% of the total resistance to CO transfer (1/TL(CO)) compared to 50% in candidates and normal subjects. CONCLUSIONS TL(CO) decline following heart transplantation is due to an increase in the intra-capillary resistance, and this appears to be due to a combination of anaemia and reduced pulmonary capillary blood volume, with the diffusing capacity of the alveolar-capillary membrane remaining unchanged.

The measurement of the single-breath transfer factor for carbon monoxide and its components using the Morgan Transflow system

In contrast to the standard single-breath transfer factor for carbon monoxide (TLCO), there are no specific guidelines or recommendations for the measurement of its components, the pulmonary capillary blood volume (VC) and membrane component (DM), by the Roughton and Forster method. Ten randomly selected heart transplant patients (three life-long non-smokers, seven ex-smokers > 1 yr, age range 24-55 years) were assessed on two occasions using either the standard or high-oxygen mixture as the first inspired gas in random order. Ten normal subjects (all non-smokers, age range 23-54 years) were assessed on two occasions using either a long protocol (30 min waiting time between repeat measurements in an individual set) or a short protocol (5 min waiting time). Two technically acceptable results of TLCO were used to derive a mean value for DM and VC for each set of measurements (Transflow, P. K. Morgan, Kent, U.K.). The different sequences of gas mixtures produced no significant differences between the values obtained in ten heart transplant patients for mean TLCO (mmol min-1 kPa-1) (standard first 5.13 +/- 1.15, high-oxygen first 5.14 +/- 1.12; limits of agreement -0.57 to 0.59 for DM or for VC. The long or short protocol produced no significant differences between the means of TLCO (mmol min-1 kPa-1) (long 8.0 +/- 1.9, short 8.0 +/- 1.9; limits of agreement -0.5 to 0.5), DM or VC. This allows the development of a standard test protocol of short duration (about 40 min) making it practical for clinical use without compromising the precision or reproducibility of the results obtained.

Marfanoid aneurysm in donor aorta after transplantation

A case is reported of dissecting aneurysm of the donor ascending aorta and root 4 years after orthotopic cardiac transplantation. The pathology raises the possibility of Marfans syndrome in the donor.

Acute adrenal insufficiency after coronary artery bypass grafting

We report a case of acute adrenal insufficiency after elective coronary artery bypass grafting. This potentially fatal complication has been reported only once before in the cardiac surgical literature, more than 15 years ago. Unfortunately, adrenal insufficiency in this setting is easily confused with the clinical picture of septic shock or an acute abdominal pathology, and it is our belief that this condition could easily escape recognition and thus contribute to needless mortality.

Inferoposterior ventricular septal rupture: Repair with maintenance of ventricular geometry

We present a method of repairing inferobasal ventricular septal rupture after myocardial infarction, preserving the ventricular cavity sizes. This may be useful when extensive infarction compromises ventricular geometry with other repair techniques.

Ventricular remodelling and revascularization in severe left ventricular dysfunction

OBJECTIVE To evaluate the role of surgical revascularization in the presence of severe, global impairment of left ventricular function without discrete aneurysm formation or mitral regurgitation. The high mortality and morbidity associated with this group, together with the limited benefits tend to prompt referral for cardiac transplantation. METHODS Fifty-three patients initially referred for transplantation, in addition to coronary revascularization, underwent mitral annuloplasty (group A = 23), free wall remodelling by endoaneurysmorrhaphy (group B = 17) or mitral annuloplasty and free wall reconstruction (group C = 13). The mean ages were 59, 56 and 57 years for groups A, B and C, respectively. Detailed assessment of pre- and post-operative physical and psychological status were carried out. RESULTS Follow-up was for a mean period of 22-26 months. All patients reported substantial improvement in quality of life, both physical and psychological parameters and in NYHA functional class status. Objective evidence of improvement in ejection fraction was seen in all three groups but especially in group A. There were five early deaths, four were due to inadequate revascularization due to the poor quality of target vessels. There were three late deaths and one patient that required transplantation. CONCLUSION We conclude that patients with severe left ventricular dysfunction can be candidates for surgical revascularization and optimization of ventricular geometry with acceptable mortality. The importance of achieving complete revascularization is emphasized in this series.

Remodelamento cirúrgico do coração no tratamento cirúrgico da cardiomiopatia isquêmica

Objective: We present a group of patients with end stage ischemic cardiomyophaty, operated with a combined procedure, involving myocardial revascularization, mitral valve anuloplasty and ventriculoplasty. Material and Methods: Twenty seven patients, 22 males, whose mean age was 57.8 years. The majority were in NYHA classes III and IV and had a mean ejection fraction of 15%. Eight patients had IABP inserted preoperatively. CPB, temperature 32° C and warm blood cardioplegia. Twenty-six received 74 grafts (3.1 per patient). 10 had Mitral anuloplasty and 4 Mitral and Tricuspid. Two cases had plication of the LV and 18 DOR procedure. The mean X-clamp time 59m and CPB time 145m. Ten patients came off Bypass on IABP and 25 required inotropic support. Results: There was no theatre mortality. Mean ventilation time 31.7h and mean ICU time 65.7h. Three patients required reventilation, 2 reexploration for bleeding, 8 developed AF and 1 had a stroke. The mean hospital stay was 13 days and 6 patients (22.2%) died in hospital. The main cause of death was low cardiac output syndrome. The minimal follow-up was 10 months and the maximum was 47 months (mean 20.7 months). Two patients died on this period. Nineteen patients were followed-up. Nineteen patients are alive (70.3%). fifteen are in NYHA class I, 2 in class II and 2 in class III. None had MI. Five patients were readmitted. The reasons for admissions were in 2 cases for AF, 2 cases angina and in 3 patients CHF. Conclusion: The cardiac surgical remodeling has high hospital mortality, but acceptable morbidity and reasonable hospital stay. The median term survival is also very acceptable giving the patients a better clinical status.