Post-infarction ventricular septal defect in Nairobi: case report.

Post infarction ventricular septal defect results from perforation of the ventricular septum secondary to ischaemic injury following myocardial infarction. Ischaemic heart disease till recently was thought to be an uncommon disease in this part of the world, but now more and more cases are being seen as a result of the changes in thelife styles of the population in this country and in the developing world in general. This is a case report of the first case of post infarction ventricular septal defect presenting to surgery for repair in this country.

Percutaneous transvenous mitral commissurotomy in juvenile mitral stenosis.

OBJECTIVE: To determine the efficacy and safety of percutaneous transvenous mitral commissurotomy (PTMC), using multi-track double balloon technique in juvenile mitral stenosis. DESIGN: Open non-randomised intervention. SETTING: Cardiac catheterisation laboratories of The Mater Hospital, The Nairobi Hospital and Kenyatta National Hospital from 1996 to 2001. PATIENTS: Forty five consecutive patients aged less than 21 years with severe pure mitral stenosis and suitable mitral valve apparatus (leaflets, chordae and papillary muscles) for successful commissurotomy. INTERVENTION: Percutaneous transvenous mitral commissurotomy under local anaesthesia. Standard left and right heart catheterisation for mitral valve disease. Trans-septal left atrial entry using standard septal puncture technique and left ventricular position secured by super-stiff guide-wire. Double-balloon mitral valvotomy on single guide-wire using multi-track balloon catheters. MAIN OUTCOME MEASURES: Mitral valve area, left atrial pressures, mitral regurgitation grade, NYHA functional class. RESULTS: Mitral valve area increased from 0.6 +/- 0.19 cm2 to 1.9 +/- 0.19 cm2 (p<0.001), left atrial pressures from 30.5 +/- 3.9 mmHg to 11.5 +/- 3.8 mmHg (p<0.001). Most patients NYHA functional class immediately improved from class III-IV to class I-II. There was no significant changes in grades of mitral regurgitation or significant complications related to the procedure. CONCLUSIONS: PTMC in juvenile mitral stenosis using the multi-track technique is safe and effective yielding satisfactory immediate results.

Treatment of severe mitral stenosis in pregnancy using multi-track mitral balloon dilatation: case report.

A case of 31-year old pregnant lady with severe mitral stenosis who benefited tremendously from multi-track balloon valvotomy is presented. She had history of cardiorespiratory arrest during delivery in the previous pregnancy and presented to the obstetrician pregnant again and symptomatic. After detailed cardiac evaluation, she was managed medically up to end of second trimester and then percutaneous balloon mitral valvotomy was done under fluoroscopy with total abdominal and pelvic shielding. The results were dramatic both in terms of haemodynamic changes and in the clinical outcome. The patient went on to give birth to a normal healthy baby. This case illustrates current management approach of mitral stenosis in pregnancy.

Percutaneous balloon mitral valvotomy: initial experience in Nairobi using a new multi-track catheter system.

OBJECTIVE: To determine efficacy and safety of the new multi-track catheter system for percutaneous baloon mitral valvotomy. DESIGN: Open, non-randomised intervention. SETTING: Cardiac catheterisation Laboratories of Mater Misericordiae Hospital (1997) and Kenyatta National Hospital, Nairobi(1994). PATIENTS: Twenty four consecutive patients with symptomatic severe pure mitral stenosis (less than 2+ mitral regurgitation) and suitable mitral valve apparatus(leaflets, chordae and papillary muscles) for successful commissurotomy. INTERVENTION: Percutaneous mitral baloon valvotomy under local anaesthesia. Standard left and right heart catheterisation for mitral valve disease. Transeptal left atrial entry using standard septal puncture technique and left ventricle position secured by single long-stiff guide-wire. Double-baloon mitral valvotomy on single guide-wire using multi-track baloon catheters. MAIN OUTCOME MEASURES: Mitral valve area, left atrial pressures, mitral regurgitation grade. RESULTS: Mitral valve area increased from 0.65 +/- 0.15cm2 to 1.98 +/- 0.34cm2 (P < 0.01), left atrial pressures from 30.5 +/- 9.1 to 11.9 +/- 5.1mmHg (P < 0.01). No significant change in mitral regurgitation grades. No complications related to multi-track technique. CONCLUSION: Percutaneous baloon mitral valvotomy using the multi track technique is effective and safe.

Pulmonary venous flow pattern in various grades of mitral regurgitation and the effect of mitral surgery on flows in severe regurgitation.

OBJECTIVE: Firstly, to describe pulmonary venous flow patterns in various grades of mitral regurgitation and secondly, to determine effect of mitral valve surgery on these flows. DESIGN: Descriptive study for the first objective and open randomised intervention for the second objective. SETTING: Mater Misericordiae Hospital Heart Unit, Nairobi (1996-1997). PATIENTS: Thirty eight consecutive patients referred to the unit with various grades of mitral regurgitation from any cause. INTERVENTION: Sixteen patients with severe mitral valve regurgitation underwent mitral valve surgery. MAIN OUTCOME MEASURES: Peak forward flow systolic velocity and peak forward flow diastolic velocity plus their velocity time integrals (VTI). Atrial contraction peak reverse flow velocity and its VTI. RESULTS: Seventy eight per cent of patients with mild (2+) mitral regurgitation (MR) had normal pulmonary venous flow. All patients with moderate (3+) MR had blunted forward systolic flow. Eighty eight per cent of patients with severe (4+) MR had reversal of the normally forward systolic flow. For the patients who had mitral valve surgery, reversed systolic flow of severe MR converted to blunted flow in 12 out of 14 patients. CONCLUSION: Pulmonary venous flow by Doppler echocardiography has potential of being a useful additional index in the grading of MR.

Effect of percutaneous balloon mitral valvotomy on pulmonary venous flow in severe mitral stenosis.

OBJECTIVE: To study the effect of percutaneous balloon mitral valvotomy (PBMV) on the deranged systolic and diastolic pulmonary venous flows in mitral stenosis. DESIGN: Open, non-randomised, case-control study. SETTING: Mater Misericordiae Cardiac Catheterisation Laboratory and Kenyatta National Hospital Cardiac Catheterisation Laboratory. PATIENTS: Twelve consecutive patients with severe symptomatic mitral stenosis with valve characteristics suitable for PBMV on echocardiographic evaluation. INTERVENTION: Percutaneous baloon mitral valvotomy. MAIN OUTCOME MEASURES: Peak systolic and diastolic pulmonary flow velocities and velocity time integrals (VTI). RESULTS: Peak sytolic pulmonary flow velocity increased from 29.8 +/- 9.6 to 46.1 +/- 8.5 cm/s p < 0.01) and systolic VTI from 2.6 +/- 1.0 to 5.5 +/- 0.9 cm (p < 0.01). Peak diastolic flow velocity increased from 39.3 +/- 5.7 to 43.0 +/- 6.9 cm/s (p < 0.05) and diastolic VTI from 3.9 +/- 1.5 to 4.8 +/- 1.6 cm (p < 0.05). Mean mitral valve area increased from 0.65 +/- 0.15 to 1.98 +/- 0.34 cm2 (p < 0.001) and mean left atrial pressures from 30.5 +/- 9.1 to 11.9 +/- 5.1 mmHg (p < 0.001). CONCLUSIONS: In patients with severe mitral stenosis and sinus rythm, left atrial filling is biphasic with diastolic preponderance. Successful PBMV causes predominant increase in atrial systolic filling.

Echocardiographic analysis of 266 patients with mitral valve disease: Results and interventional implications

Two hundred and sixty six patients (157 females and 109 males) aged nine to 58 years (mean: 29 years); with mitral valve disease of various aetiologies underwent clinical electrocardiographic; roentgenographic and detailed 2-D-colour-doppler echocardiographic evaluations. They were seen between June; 1993 and June; 1995 within an on-going mitral valve analysis project conducted in three major hosptials in Nairobi. As expected in this environment; majority (77 per cent ) of the valve lesions were of rheumatic aetiology; and of severe grades (41-48 per cent). Majority of patients with mitral stenosis were found to suitable for either mitral valvotomy (by baloon catheter or surgery) or mitral valve repair (72.3 per cent); the rest; 27.7 per cent; requiring mitral valve replacement. Nearly 42 per cent of mitral stenosis patients were suitalbe for percutaneous mitral baloon valvotomy. Mitral valve repair was found possible in 56.3 per cent of patients with predominant mitral regurgitation; while only 36.5 per cent were suitable for valve repair in those with mixed regurgitaion and stenosis. With the developments in echocardiography; inteventional catheterisation and valve repair techniques; many options for intervention are now available ot patients suffering from mitral valve disease

Percutaneous transluminal balloon valvuloplasty for pulmonary valve stenosis: report on six cases.

Percutaneous transluminal baloon valvuloplasty is currently the treatment of choice for most cases of pulmonary valve stenosis. In the first series of cases performed at Kenyatta National Hospital, six patients aged 4 to 24 years with severe pulmonary valve stenosis and no other associated cardiac lesions were selected for the procedure. Immediately following baloon valvuloplasty, the pressure gradients across pulmonary valve measured by both echo-Doppler technique and cardiac catheterisation dropped very significantly (P < 0.001). Catheterisation peak systolic gradients (psg) dropped from 162.5 +/- 23.7 to 56.5 +/- 19.0 while echo-Doppler pressure gradients dropped from 112.0 +/- 11.9 to 42.8 +/- 16.0. No complications occurred during or after the procedure. This initial short-term experience in our set-up confirms the safety and effectiveness of this procedure. Furthermore, this procedure is much cheaper and technically easier to perform than cardiac surgery.

Cardiovascular risk factor profiles in mild to moderate hypertensives seen at Kenyatta National Hospital.

Sixty newly diagnosed adult patients with mild to moderate essential hypertension were assessed to determine their cardiovascular risk factor profiles. Detailed history and physical examinations were done. Resting 12-lead ECG was done and serum levels of uric acid, fasting cholesterol, and fasting glucose were determined. Twenty nine patients had hypertension and two or more cardiovascular risk factors. The most prevalent cardiovascular risk factors other than hypertension were electro-cardiovascular left ventricular hypertrophy (31.7%), obesity (28.3%) and hypercholesterolaemia (28.3%). About a half of these patients (48.3%) can be classified as high risk hypertensives. This calls for aggressive management of cardiovascular risk factors as a whole and not just hypertension alone if we are to reduce incidence of hypertensive complications.

Metabolic effects of propranolol and hydroflumethiazide treatment in Kenyans with mild to moderate essential hypertension.

In a prospective single-blind comparative trial, sixty newly diagnosed mild to moderate hypertensives were randomly assigned to either propranolol or hydroflumethiazide monotherapy. Baseline fasting serum glucose lipid profiles, serum uric acid and potassium levels, were determined at the beginning of the trial. Repeat levels were determined at completion of twelve weeks of treatment. Propranolol treatment significantly reduced HDL-cholesterol (p < 0.02) and increased both VLDL and total serum triglycerides (p < 0.01). Hydroflumethiazide significantly increased total and LDL-chole-sterol, fasting serum glucose and uric acid levels (p < 0.01); potassium levels were significantly lowered (p < 0.01). Treatment with either propranolol or hydroflumethiazide is associated with significant metabolic side-effects which require regular monitoring and intervention as appropriate.

Influence of beta-blockade with beta-1-selectivity or intrinsic sympathomimetic activity on some metabolic responses to exercise.

Beta-blockers that are non-selective, beta-1-selective or possess intrinsic sympathomimetic activity (ISA) are thought to differ in their effects on serum potassium, glucose and lactate during exercise. In a randomized, double-blind, cross-over, placebo-controlled study, 21 healthy male volunteers took placebo, propranolol, pindolol and metoprolol on separate occasions. They were subsequently exercised using the same exercise protocol on each visit and serum levels of potassium, glucose and lactate determined before and after exercise. Only propranolol (non-selective beta-blocker with no ISA) was associated with significantly higher increases in serum potassium and glucose than placebo (p = 0.000). Increases in serum lactate levels with exercise were not significantly different between propranolol, pindolol (non selective blockers with ISA), metoprolol (beta-1-selective blocker with ISA) and placebo. Interference with metabolic responses to exercise associated with beta-blockade is modified by beta-1-selectivity and ISA amongst indigenous Kenyans.

Influence of beta-blockade with beta-1-selectivity or intrinsic sympathomimetic activity on some cardiorespiratory responses to exercise.

Possession of beta-1-selectivity and intrinsic sympathomimetic activity (ISA) by beta-adrenergic blocking drugs have been found to modify the effects of these drugs on heart rate, blood pressure and pulmonary airway resistance both at rest and during exercise. In a randomised, double-blind, cross-over, placebo-controlled trial, 21 healthy male volunteers took placebo, propranolol (non-selective with no ISA), metoprolol (beta-1-selective with no ISA) and pindolol (non-selective with ISA) on separate occasions prior to an exercise test using the same protocol each time. Heart rate, blood pressure and peak respiratory flow rate (PEFR) were measured before exercise and at exhaustion. No significant differences in percentage increase in heart rate after exercise were detected between placebo and all the three beta-blockers. All three drugs were associated with significantly lower percentage increases in systolic blood pressure with exercise compared to placebo; with metoprolol and propranolol causing lower increases than pindolol. The index of myocardial oxygen consumption, MVO2, was highest with pindolol. PEFR was reduced most by propranolol. Possession of beta-1-selectivity and ISA by beta-blocking drugs modifies their effects on cardio-respiratory responses to exercise amongst indigenous Kenyans.

Comparative study of the efficacy and tolerability of hydroflumethiazide versus propranolol in Africans with mild to moderate hypertension.

Sixty patients with Diastolic Blood Pressure (DBP) of 100-110mmHg matched for age, sex and Bp levels were randomly assigned to propranolol 80mg daily or Hydroflumethiazide (HFM) 50mg daily. HFM causes a significant reduction in systolic blood pressure (SBP) and DBP within 4 weeks compared both with baseline and propranolol (SBP 143.7 +/- 12.3 vs 158.1 +/- 10.9mmHg, P < 0.05; DBP 92.0 +/- 4.5 vs 102.4 +/- 5.1mmHg, P < 0.05), (SBP 143.7 +/- 12.2 vs 152 +/- 11.0mmHg P < 0.05; DBP 92.0 +/- 4.5 vs 101.1 +/- 6.1mmHg, P < 0.05), respectively. Propranolol produced no significant difference from the baseline at 4 weeks (SBP 152.0 +/- H.0 vs 154.1 +/- 11.5mmHg NS; DBP 101.1 +/- 6.1 vs 102.2 +/- 5.6mmHg, NS). Reduction in BP by HFM was maintained after 8 and 12 weeks with further reduction but which did not achieve statistical significance. Increased dose of propranolol (160mg daily) after 4 weeks caused significant reduction in BP by 8 week (SBP 146.8 +/- 11.8 vs 152.0 +/- 11.0mmHg, P < 0.05; DBP 95.9 +/- 4.4 vs 101.1 +/- 6.1mmHg P < 0.05), which was maintained upto 12 weeks. The values however remained higher than in the HFM group. More patients in the HFM group achieved target BP (< 140/90), SBP 53.8% vs 29.6% P < 0.05, DBP 69.2% vs 14.8% P < 0.01. Incidence of side effects was similar and will be discussed. Thiazides are superior to B'blockers as initial monotherapy in black hypertensives.