Prevalence of mitral valve prolapse in Saudi sickle cell disease patients in Dammam - A prospective-controlled echocardiographic study.

Mitral valve prolapse (MVP) is the most common valvular heart disease and there are numerous reports of a strong association with many conditions including sickle cell disease (SCD). Since SCD is very common in the Eastern Province of Saudi Arabia, we undertook a prospective controlled study to determine and compare the prevalence of MVP in the SCD patients with other groups of subjects. Three hundred and sixteen subjects (156 males and 160 females) were studied. They were divided into four groups based on their hematologic diagnoses - I SCD, II normal controls, III sickle cell traits, IV other anemias. The prevalence of MVP is 17.4% in Group I, 13.3% in Group II, 21.4% in Group III and 19.4% in Group IV. There was no statistically significant difference in the prevalence of MVP among the four study groups. In contrast to a previous study, these results show that the prevalence of MVP by echocardiographic criteria (M-mode and 2-dimensional) in SCD patients is the same as in the general population. We believe that mere case-reporting and lack of or inappropriate control in most of the clinical series are responsible for the wide range of conditions claimed to be associated with MVP.

Clinical profile of patients admitted to the coronary care unit with possible myocardial infarction without diagnostic ECG and/or enzyme changes.

Concern has been expressed about the cost-effectiveness of the Coronary Care Unit (CCU) and solution options offered on account of the large number of patients admitted to the CCU who turn out not to have acute myocardial infarction. In a prospective study over four years, we studied a group of patients admitted to the CCU with suspected myocardial infarction but who did not have diagnostic ECG and/or enzyme changes for the causes of their chest pain. We compared the clinical profile of these patients (Group A) with that of a random sample of patients with confirmed myocardial infarction (Group B). Gastrointestinal disorders, musculoskeletal chest pain, panic and anxiety disorders were the major causes of chest pain in Group A patients. A normal ECG and a normal creatine phosphokinase (CPK) within the first 24 hours, a normal initial random blood sugar, a younger age and absence of coronary risk factors effectively separated Group A patients as low risk from Group B patients as high risk for acute myocardial infarction. These simple parameters will assist physicians providing CCU care in most hospitals in early decision making and in the judicious use of the CCU.

Low protein/high calorie dietary regimen in the management of chronic renal failure. A preliminary study of Nigerian patients.

The progression of renal failure was evaluated in seven patients with established chronic renal failure (mean serum creatinine 4.17 mg%), while on a supervised dietary regimen consisting of low protein of high biological value (20-30 g/day), and a high calorie content (3000 kcal/day) for a period of between 18 and 28 months. Five other patients with a comparable degree of chronic renal failure whose protein intake was unrestricted (evaluated to vary between 40 and 60 g per day) served as controls. In the study group, serum creatinine levels stabilized or improved in five, while a moderate rise was observed in two. In contrast, a considerable and significant rise in serum creatinine values was observed in all the controls. Two significantly different slopes (P less than 0.01) were also obtained from the linear regression analysis of the reciprocal of serum creatinine values against time, for the two groups. Our preliminary observation of a beneficial effect of this regimen in our patients is particularly relevant to the developing countries because of the high prevalence of chronic renal failure against the background of grossly inadequate facilities for maintenance dialysis or renal transplantation.

Cardiovascular responses to exercise in essential hypertension.

Cardiovascular responses to treadmill exercise were studied using the Bruce protocol in 40 patients with essential hypertension (20 males; 20 females) and 36 normotensive controls (20 males; 16 females) with similar age, level of habitual physical activity, smoking and alcohol habits. Maximal heart rate (MHR) was significantly lower in hypertensives than normotensives but there was no significant difference when treated were compared with untreated male hypertensives. Rest -maximal change in heart rate (delta HR) was lower in hypertensives than normotensives (males P less than 0.02). The blood pressure (BP) response was significantly higher in hypertensives than normotensives and in untreated than treated hypertensive males. The delta SBP was not significantly different in hypertensives and normotensives. The mean PRP max was significantly higher in male hypertensives than normotensives, lower in treated vs untreated male hypertensives; similar in treated hypertensives and normotensives and also in female hypertensives (mainly a treated group) compared with controls. The cardiovascular responses to exercise in the hypertensive population studied were significantly different from normotensives. The benefit of treatment of hypertensives is further emphasized by the reduction in blood pressure response to exercise and the reduced myocardial oxygen consumption during maximal exercise.

A therapeutic audit in the management of hypertension in Nigerians.

The prevalence of hypertension in adult Nigerians is about 20% and hypertension remains a significant risk factor in cardiovascular morbidity and mortality. In Africans, hypertension carries a dismal prognosis, has a late clinical presentation and certain antihypertensives may be less effective. We therefore conducted a therapeutic audit in order to assess the initial cardiovascular risk profile of Nigerian patients as well as the safety and efficacy of different antihypertensive agents. A cross-sectional survey of 367 patients (M:F:2:1) modal age 25-44 years, mostly WHO II, enrolled in our clinic was undertaken. 56% had been on treatment for up to one year and 2% for longer than ten years. 12.5% had concomitant diabetes mellitus. Statistical analyses of drug efficacy were done by Spearman correlation and Analysis of Variance (ANOVA). The rank order of hypertensive efficacy was as follows: Thiazides (T) (r = 0.57, P less than 0.05), T + Methyldopa (M) (r = 0.91, P less than 0.001) T + M + Hydralazine (r = 0.92, P less than 0.001). Neither propranolol, nor frusemide showed significant overall efficacy. However, propranolol appeared efficacious in hypertensives with renal impairment. Postural dizziness was occasionally reported. Total mortality was 6% occurring mostly in the modal age group. Diabetic hypertensives had a 5 fold enhanced risk of a fatal outcome (X2 P less than 0.001). Our findings support a rational stepped care approach to pharmacotherapy of hypertension in black Africans, a cost-effectiveness analysis of common antihypertensives; it elucidates the associated adverse effects to patients, and draws attention to the lethality of concomitant hypertension and diabetes. Prospective large scale studies of the treatment of hypertension in Africans are required.

Cardiovascular responses to maximal treadmill exercise in healthy adult Nigerians.

Maximum treadmill exercise, using the Bruce protocol was performed on 124 healthy Nigerians (80 males and 44 females) aged 20-59 years. The mean duration of exercise (DOE) and estimated maximal oxygen uptake (VO2 max) decreased linearly with increase in age with a high correlation between age and VO2 max (r = -0.82). Males and active subjects had significantly higher values than females and sedentary subjects respectively. From this study, average values of VO2 max in healthy Nigerian men and women can be predicted from the following regression equations for VO2 max (ml of O2 per kg of body weight per min): Sedentary men = 57.2 - 0.528 (years of age) (r = -0.85), Active men = 65.0 - 0.579 (years of age) (r = -0.82), Sedentary women = 34.6 - 0.236 (years of age) (r = -0.61). The regression equation for active women is not predictive as none above the age of 29 years volunteered to participate in this study. The mean maximal heart rate (MHR) was inversely related to age (r = -0.51) and average value of MHR (beats/min) expected in healthy Nigerian men and women can be predicted from the regression equation below: MHR = 207 - 0.620 (age in years) (r = -0.51). This study presents reference data for the assessment of cardiovascular fitness of Nigerians with or without cardiovascular disease.

Diseases causing chronic renal failure in Nigerians--a prospective study of 100 cases.

There are indications that there is an increased risk of chronic renal failure (CRF) in the Negroid race, yet few studies have been carried out in the native 'black' environment. A clinico-pathological study of 100 consecutive Nigerian subjects with CRF, seen over a 3-year period, is presented. Primary chronic glomerulonephritis (CGN) accounted for 50, accelerated hypertension for 25, and various aetiological entities for a further nine; these included, chronic pyelonephritis (two), diabetic nephropathy (two), calculous nephropathy (one), toxaemia of pregnancy (one), renal dysplasia (one), tuberculosis (one) and polycystic disease in the ninth subject. In 16 cases, no definitive aetiological diagnosis could be made. Combinations of the following features, protracted hypertension, proteinuria, significant analgesic intake and gouty arthritis, were observed. CGN and accelerated hypertension still remain the leading causes of CRF, while diseases such as diabetes mellitus and chronic pyelonephritis do not contribute significantly to CRF in Nigerians. Recognition of the early features and the causes of CRF would considerably reduce the prevalence of this condition.

Enalapril in African patients with congestive cardiac failure.

In a preliminary double-blind study in African patients with heart failure, enalapril tended to increase treadmill exercise duration relative to placebo (95% confidence interval--11.5 to 144.3 s). This was associated with a significant improvement in NYHA functional class and subjective well being (P less than 0.05 ANOVA) with a concomitant reduction in body weight (P less than 0.05 ANOVA). It significantly increased pulse pressure during forearm isometric exercise (P less than 0.05 ANOVA), but the Valsalva's manoeuvre and the orthostatic response were unchanged.

Enalapril and hydrochlorothiazide in hypertensive Africans.

The antihypertensive efficacy both of angiotensin converting enzyme (ACE) inhibitors and thiazide diuretics has been claimed to be influenced by plasma renin activity, which declines with age and is low in blacks. In a double-blind, placebo-controlled, double-dummy, randomized, parallel-group preliminary study, the antihypertensive efficacy and tolerability of the ACE inhibitor enalapril (20 mg day-1) and hydrochlorothiazide (50 mg day-1) were evaluated and compared for 4 weeks in 20 African patients with essential hypertension. The two groups had similar baseline clinical features and serum Na+ and K+ levels. Hydrochlorothiazide caused a significant and sustained fall in erect blood pressure with a reflex tachycardia. Enalapril exerted only a modest antihypertensive action, but significantly reduced erect heart rate. Direct comparison of hydrochlorothiazide- and enalapril-induced hypotension suggested a greater fall in subjects on the thiazide. The 95% confidence limits for the thiazide-enalapril difference in antihypertensive action at the end of the study was 39.5 to -7.5 mm Hg systolic and 22.0 to -6.6 mm Hg diastolic. The maximal blood pressure fall after hydrochlorothiazide was positively correlated with age (r = 0.50; p less than 0.05), whilst that of enalapril was inversely related age to (r = -0.57, p less than 0.05). The results are compatible with the notion that ACE inhibitor monotherapy may be less effective than thiazide diuretic treatment in African and black patients with essential hypertension. The findings also support the concept that age and racial factors may influence the response to antihypertensive treatment.

Spectrum of treadmill exercise responses in Africans with normotension, essential hypertension and hypertensive heart failure.

Hypertension is an important and common risk factor for cardiovascular morbidity and mortality in Africans. In Africans, hypertension carries a more dismal prognosis for target organ damage. We therefore studied the influence of blood pressure on treadmill exercise performance in normotensives, hypertensives and patients with hypertensive heart failure, matched for age and sex. The spectrum of response was a progressive diminution of the systolic rise in blood pressure during exercise, exercise-induced tachycardia, exercise time, and maximal oxygen intake. There was an increase in functional aerobic impairment with a rank order from normotensives to WHO I hypertensives, then WHO II, with a non-linear extreme rise with the onset of heart failure. The results indicate that impaired exercise performance in African hypertensives occurs with the onset of ventricular hypertrophy, and that this is accentuated by the neuroendocrine response in congestive heart failure.

Renal function in adult Nigerian diabetics.

Renal function was studied in 31 stable adult diabetic patients and 17 healthy non-diabetic adults of similar age groups and sex distribution. 14 patients (45%) were insulin dependent and 9 (27%) were hypertensive. Glomerular function was studied by creatinine clearance and 24 hour urinary protein excretion, tubular function early morning urine concentration, urine pH and urinary excretion of sodium, potassium and uric acid. 24 hour urine protein excretion was significantly higher (p less than 0.05) in the diabetics than the controls, mean values 345 +/- 94.5 mg and 109 +/- 10 mg, respectively. 42% of the patients had values well above 200 mg per day in contrast to 16% with clinical proteinuria by albustix testing. 24 hour protein excretion was higher in insulin dependent diabetic than in non-insulin diabetic patients. Mean values of creatinine clearance were similar in diabetics and controls. Increased uric acid excretion was observed in the diabetic patients. This study emphasizes the superiority of 24 hours urinary protein estimation in the detection of early nephropathy in diabetic patients. Further studies to elucidate the mechanisms and implication of the hyperuricosuria need to be carried out.

Blood pressure distribution of Nigerians in the first two decades of life.

The systolic and diastolic blood pressures of 2301 Nigerian boys and 2017 Nigerian girls were measured. Their ages, which were in the range 1-20 years, heights and weights were also recorded. The relationship between these variables are discussed. Selected percentiles of systolic and diastolic pressures for different ages and weights are given.

Complete heart block in chronic chloroquine poisoning.

Complete heart block of recent onset is reported and is attributed to chronic chloroquine abuse. Total blood chloroquine was more than two times higher in this patient than in 4 patients following therapeutic doses of chloroquine, and chloroquine basic metabolites were also proportionally higher in this patient's blood.

Alpha 1-antitrypsin phenotypes in a Nigerian population.

Alpha 1-antitrypsin phenotypes of 350 normal Nigerian blood donors were determined by isoelectric focusing in polyacrylamide gel. The distributions obtained (MM, 66.86%; MS, 16.29%; MZ, 0.57%; SS, 2.0%; SZ, 0.28%) were different from those reported for caucasian populations. Forty-nine of these donors could not be classified into any of the above common phenotypes suggesting that some rare alleles occur in Nigeria. The probable cause and implications of the high frequency of the S gene in the Nigerian population are discussed.

Hypertensive retinopathy in Nigerians. A prospective clinical study of 350 cases.

In a prospective study of retinal changes in 350 hypertensive Nigerians from two institutions, over 70% of the patients showed hypertensive retinopathy. This is in agreement with the findings of some other studies in Africans. There was a statistically significant correlation between the height of blood pressure and severity of retinal changes. There was also a significant correlation between age and the early retinal changes but there was no environmental influence on the percentage distribution of retinopathy between the two institutions studied.

Congestive cardiac failure in elderly Nigerians: a prospective clinical study.

A prospective study of congestive cardiac failure in 221 elderly Nigerians seen at Ahmadu Bello University Hospital, Zaria, and Ife University Teaching Hospitals Complex, Ile-Ife from 1974 to 1979 is reported. Hypertension, iodopathic cardiomegaly and pulmonary heart disease were major causes of cardiac failure. No case of coronary atherosclerotic heart disease was seen. Ventricular conduction defect was the commonest E.C.G. abnormality recorded. In over half of the patients, there was coexisting disease, mild to moderate anaemia being the most common.

Serial measurements of left ventricular dimensions by echocardiography. Assessment of week-to-week, inter- and intraobserver variability in normal subjects and patients with valvular heart disease.

The week-to-week, inter- and intraobserver variation in left ventricular echocardiographic measurements has been studied in 10 normal male volunteers and in five patients with stable valvular disease. A two-way analysis of variance showed no statistically significant variation either from week to week or between observers. Furthermore the within observer variation was minimal. Calculation of the coefficient of variation allowed confidence limits to be applied to each of the six ventricular measurements, thus providing ranges of variation in follow-up studies using M-mode echocardiography.

Alpha-1-antitrypsin levels and phenotypes in some healthy Nigerians--. A preliminary report.

Levels of serum Alpha-1-Antitrypsin were determined in 59 healthy adults and in-cord samples of 42 newborn Nigerians using the immunochemical method of Mancini. The protease inhibitor phenotypes were also determined in these samples by Iso-electric focusing in an LKB multiphor electrophoresis system. The mean adult serum level was 106% of internationally accepted levels. The mean cord level was 75% of the adult mean. The finding of a rare genetic variant 'S' in two of the 96 sera is higher than figures hitherto quoted in the literature. We thus believe that it will be very interesting to study a larger sample of Nigerians in the future.