Intermittent transdermal nitrates do not improve ischemia in patients taking beta-blockers or calcium antagonists: potential role of rebound ischemia during the nitrate-free period.

OBJECTIVES: This study was conducted to determine whether rebound ischemia occurs during nitrate-free periods with intermittent cutaneous nitroglycerin therapy in patients with angina pectoris who are receiving background antianginal therapy. BACKGROUND: Rebound angina has been suggested to be a complication of the nitrate-free period with long-term cutaneous nitroglycerin therapy given intermittently to prevent tolerance. METHODS: Fifty-two patients with stable effort angina taking either a beta-adrenergic blocking agent (n = 25) or diltiazem (n = 22) or their combination (n = 5) completed a randomized, double-blind, placebo-controlled crossover study of cutaneous nitroglycerin patches (50 mg). Active or placebo patches were worn for 1 week, applied at 8 AM and removed at 10 PM to provide a 10-h daily nitrate-free (or placebo-free) period. During the last 48 h of each study phase, a Holter monitor was used to detect ischemia. RESULTS: Only 31 patients experienced ischemia during either phase of the study (23 during the patch-off period). A total of 463 ischemic episodes were recorded: 246 during placebo and 217 during nitroglycerin (p = 0.8, for per patient comparison). The majority (88%) of ischemic episodes were silent. Mean (+/- SEM) duration of ischemia during the total 48-h period was similar during active and placebo phases (35.5 +/- 15.0 min/24 h for active therapy vs. 29.7 +/- 9.8 for placebo, p = 0.8). This was due to an increase in duration of ischemia with active therapy during the patch-off period (46.9 +/- 17.9 min/24 h for active therapy vs. 22.5 +/- 9.2 for placebo, p = 0.07) and a decrease during the patch-on period (27.5 +/- 14.0 min/24 h for active therapy vs. 34.5 +/- 11.0 min/24 h for placebo, p = 0.16). The pattern of diurnal distribution of ischemic episodes differed between active and placebo phases. During placebo there was a nadir in the incidence of ischemia in the overnight patch-off period, with a significantly lower incidence between midnight and 6 AM (25 episodes) compared with the mean number of episodes during the three other 6-h periods (73 episodes, p < 0.001). During the nitroglycerin patch-off period, there was a loss of this overnight nadir, with the same incidence of ischemia between midnight and 6 AM (53 episodes) as the mean number of episodes for the three other 6-h periods (54 episodes). CONCLUSIONS: The majority of patients taking background antianginal therapy experienced no ischemia during the patch-off period. In the 44% of patients with ischemia during this period, there was a nonsignificant increase in the duration of ischemia with active therapy. Although this result was statistically inconclusive, the change in the distribution of diurnal ischemia offers suggestive evidence that rebound ischemia may be a problem with regard to intermittent cutaneous nitroglycerin.

Coronary artery reoperations using arterial conduits: immediate and early results.

This study deals with results of coronary artery reoperations in 21 males aged 54.4 +/- 6.6 years. Native vessel coronary disease at first and second operation was nearly the same (2.7 +/- 0.6 vs 2.8 +/- 0.4 vessel, p = NS). Graft attrition and deterioration in left ventricular ejection fraction (55.9 +/- 9.2 initial vs 36 +/- 15 at reoperation, p < 0.001) necessitated reoperation in majority. Recurrence of angina (71%) and left ventricular failure (23.8%) were the clinical indicators for reoperation. Procedure was successful in 20 (95%) and had to be abandoned in 1 due to severe pericardial and sternal adhesions. Arterial grafts were utilised in 90% (18 cases, Group A and B). Total arterial revascularisation (Group A) was done in 9 (45%) using Y graft 6, combination of both mammary arteries 2, and by both mammary and inferior epigastric artery in 1. Group B patients had arterial grafts (bilateral IMA 1, Y graft 1, bilateral IMA + gastroepipolic 1, RIMA 4, and LIMA 2) in addition to a venous graft. Two patients (group C, 10%) had only venous grafts. There was no in hospital mortality or morbidity and at 10 +/- 5.2 months follow up, all are asymptomatic with negative stress test at 3 months followup in 8 cases. We conclude that coronary artery reoperations using arterial conduits can be performed safely with excellent immediate and early results.

The upper limit of alveolar capillary recruitment in a young man with lung growth impairment.

In order to obtain further insight into the adaptive mechanisms relating to gas exchange in anatomically small lungs, tests of mechanical lung function and gas exchange were made in an active young man, whose lung growth had been severely impaired due to pectus excavatum developed in childhood. We found our patient to have small (total lung capacity, 59% of predicted) but mechanically normal lungs. He had a normal cardiac output, a normal single-breath diffusing capacity (100% pred), and a high diffusion coefficient (148% pred) associated with a high pulmonary capillary blood volume (131% pred) at rest. Pulmonary distensibility (K) and elastic recoil were normal. During steady-state exercise he was unable to recruit further reserves of pulmonary capillaries, but this was not reflected in a plateau for oxygen consumption, which was presumably the result of an increased pulmonary capillary blood flow rather than volume. The recruitment of pulmonary capillary reserves in this young man has enabled him to maintain a normal maximum exercise capacity. In addition, the high stroke volume and a haemoglobin level in the high normal range (176 g.l-1) may have maintained his maximal exercise function, despite fewer alveolar units. This study suggests that, contrary to previous findings, loss of a major proportion of lung tissue need not impair exercise capacity. Patients with either small lungs or following pneumonectomy may benefit from physical training sufficient to optimize both an increase in cardiac output and recruitment of their existing alveolar capillary reserves.

Total anomalous pulmonary venous connection: asymptomatic survival for 50 years without surgical intervention.

Total anomalous pulmonary venous connection (TAPVC) is an uncommon cyanotic heart disease and survival beyond infancy is rare. We report a patient of TAPVC of the supracardiac variety who has survived till the age of 50 years without surgery.

Intracranial arteriovenous malformation masquerading as a cardiac disorder.

In this report, we describe an adult with a large intracranial arteriovenous malformation which mimicked a cardiac lesion. The patient presented with predominant cardiac symptoms, a prominent continuous murmur and signs of arterial run-off. The diagnosis was confirmed by digital subtraction angiography. We report the case to highlight the rare presentation.

Concurrent double balloon valvotomy for combined rheumatic mitral and tricuspid stenosis.

We expanded the application of percutaneous balloon valvotomy (PBV) to 4 adults (age 14 to 30 years, average 22.2 years) with combined rheumatic mitral and tricuspid stenosis. Double balloon dilatation reduced the transmitral gradient from 17.36 +/- 3.54 to 5.52 +/- 0.89 (P less than 0.025) and transtricuspid gradient from 12.65 +/- 2.67 to 3.67 +/- 0.95 (P less than 0.025). Mitral and tricuspid valve area increased from 0.73 +/- 0.20 to 2.57 +/- 0.67 (P less than 0.005) and from 0.77 +/- 0.24 to 2.67 +/- 0.24 cm2 (P less than 0.005), respectively. The procedures were well tolerated, with no significant increase in valvular regurgitation or left to right shunt across the atrial septum. The excellent symptomatic and haemodynamic benefits are sustained at 3-24 months follow-up. It is concluded that combined dilatation of stenotic valves by double balloon technique can emerge as an alternative to surgery in selected patients with polyvalvar rheumatic heart disease.

Balloon mitral valvotomy in a patient with Ebstein's anomaly of tricuspid valve and rheumatic mitral stenosis.

We report a young woman with Ebstein's anomaly of tricuspid valve and rheumatic mitral stenosis who successfully underwent mitral valvotomy using double balloon technique. The clinical and haemodynamic benefits are sustained at 1 year followup.

Coarctation of aorta with unusual association of diverticulum of the left ventricle and double orifice mitral valve.

We describe a case of coarctation of aorta with two unusual associated anomalies, namely, a diverticulum of the left ventricle and double orifice of the mitral valve. Echocardiography and colour flow mapping precisely diagnosed the bridging tongue of leaflet tissue responsible for the double orifice of the mitral valve. Balloon angioplasty for coarctation produced dramatic benefits which are sustained at follow-up. The other two lesions caused no haemodynamic abnormality.

Percutaneous balloon valvotomy for aortic valve stenosis using single or double balloon technique.

Percutaneous balloon valvotomy was performed in 21 cases (aged 6 to 62 years) with moderate to severe aortic valve stenosis, using either single (16 cases) or double balloon (5 cases) technique. All patients had basal transaortic pressure gradient 50 mmHG or above. A majority of patients had significant haemodynamic improvement immediately following balloon dilatation. The mean systolic transaortic pressure gradient reduced from 94 mmHg (range 50 to 160) to 42 mmHg (range 14 to 82; P less than 0.05) immediately after the dilatation. The final gradient was less than 40 mmHg in 11 cases. The mean cardiac index improved from 3.86 L/min/M2 (range 2.8 to 5.2) to 4.14 L/min/M2 (range 3.4 to 5.6; P:NS) following the procedure. There was no death or major complication related to the intervention. There was a procedure-related mild aortic regurgitation in 4 cases. We conclude that percutaneous balloon dilatation is an effective, safe, low cost, nonsurgical method for treating patients with aortic valve stenosis.

Profile of submitral left ventricular aneurysms in Indian patients.

Annular subvalvar aneurysms of the left ventricle initially described from Nigeria are considered to be rare in India. We report 6 such cases studied clinically and by noninvasive and invasive investigations during the last 8 years. In 4 cases morphologic documentation was available at surgery or autopsy. The clinical picture was dominated by congestive cardiac failure and mitral regurgitation and most of the patients were young. Echocardiographic studies provided the precise noninvasive diagnosis by demonstrating large aneurysms arising below the posterior mitral leaflet. In one case the submitral left ventricular aneurysm extended into the left atrium. The mortality was high in unoperated cases and operative repair under cardiopulmonary bypass is the most appropriate management.

Noninvasive and invasive evaluation of left bundle branch block (LBBB).

Nineteen patients with LBBB were studied by clinical, electrocardiographic (ECG), echocardiographic, electrophysiological and coronary angiographic examination. The commonest etiology of LBBB observed was idiopathic/degenerative in 10 (52.6%), followed by atherosclerotic coronary artery disease in 6 (31.5%) and hypertrophic cardiomyopathy, dilated cardiomyopathy and systemic hypertension in 1 case each (15.7%). In all patients with coronary artery disease (CAD), significant lesion of the left anterior descending artery was observed. On ECG, presence of Q in I, aVL, V5 or V6 was most helpful in predicting the presence of CAD while primary T-wave changes were least helpful. The degree of QRS axis was not helpful in predicting the presence as well as severity of CAD. Altered septal/regional wall motion abnormalities were commonly encountered on echocardiography and left ventriculography. Although infrahisian conduction delay was frequently observed and 11 (61.1%) had prolonged HV interval, in 2 of these there was additional suprahisian conduction delay. All patients with prolonged PR interval (more than or equal to 200 msec) or wide QRS duration (more than 140 msec) had infrahisian block with or without associated suprahisian block. Hence, hemodynamic evaluation, coronary angiographic studies and electrophysiological evaluation is essential in patients with LBBB.