Normal Limits of Electrocardiogram and Cut-Off Values for Left Ventricular Hypertrophy in Young Adult Nigerians

This study assessed healthy young adults to determine the normal limits for electrocardiographic variables and cut-off values for left ventricular hypertrophy. It was a cross sectional descriptive study in which the participants were evaluated clinically by standard 12-lead resting electrocardiogram (ECG) at 25mm/s during quiet respiration. The heart rate, P wave duration, axis and amplitude, PR and QT intervals, QRS duration, axis and amplitude and T wave axis were assessed. Three hundred and twenty four (324) volunteers comprising of 175 males and 149 females aged 20 to 30 years (mean, 23.01±2.88years) participated in the study. The normal limits for heart rate, P wave duration, amplitude and axis in lead II, QRS duration and axis, T wave axis, PR interval, QT interval and QTc respectively were; 61-93beats per  minute,0.08-0.12s,1.00-2.00mm,22.00-79.000,78.00-106.00ms,15.50-81.000, 24.25-69.000,0.12-0.19s, 0.32-0.40s and 0.36-0.44s. The cut-off values for Sokolow-Lyon, Cornell and Araoye criteria for assessment of left ventricular hypertrophy (LVH) were higher than those previously in use in  medical practice. Gender difference exists in some cut-off values for LVH. This study defined the normal limits for electrocardiographic variables for young adult Nigerians. Racial factor should be taken into consideration in interpretation of ECG.Keywords: Normal limits, Electrocardiogram, Cut-off values, Left ventricular hypertrophy, Young Adult

Evaluation of renal volume by ultrasonography in patients with essential hypertension in Ile-Ife, south western Nigeria

Background and aims: To determine renal volume in adult patients with essential hypertension and correlate it with age, sex, body mass index (BMI), body surface area (BSA) and duration of hypertension. Patients and methods: A total of 150 patients (75 males, 75 females) with essential hypertension and normal renal status were evaluated sonographically in this prospective study. Fifty healthy individuals (25 males, 25 females) without hypertension were also evaluated as control. Renal volume was then calculated from the kidney’s length, width and anterio-posterior diameter using the formula L*W*AP*0.523. Results: The range of renal volume obtained was 51.65-205.02 cm3, with a mean of 114.06±29.78 cm3 for the left kidney and 47.37-177.50 cm3 with a mean of 106.14±25.42 cm3 for the right kidney. The mean volumes of the right and left kidneys in males (112.98±25.56 cm3 and 123.11±32.49 cm3, respectively), were significantly higher than in females (99.31±23.07 cm3 and 105.01±23.77 cm3, respectively). Renal volume correlated significantly with BSA and BMI, but decreased with age. The renal volume showed no correlation with duration of hypertension. Conclusion: Renal volume is higher in the left than the right kidney in hypertensive patients of both sexes and female hypertensive patients have smaller kidney size compared to males. The study also shows that volume of both kidneys decreases with age and positive correlation between renal volume, BSA and BMI. However, there is no correlation between renal size and duration of hypertension.Keywords: essential hypertension; renal volume; ultrasonograph

Prediction of functional capacity during six – minute walk among patients with chronic heart failure

Formulae for predicting functional capacity during 6-minue walk are lacking and the accuracy of the existing formulae has been challenged in deferent populations. The purpose of this study was to develop an equation that would be useful in predicting functional capacity in form of maximum oxygen consumption) (V0 ) in Chronic Heart Failure Patients (CHF) during exercise.Sixty-five subjects were recruited for the study. The procedure required the subjects to walk on a self paced speed on a 20 meter marked level ground for 6 minutes. The distance covered in 6 minutes was measured and the speed calculated.The result showed that the distance covered was highly correlated with the VO2 (0.65, p< 0.01). The regression analysis revealed that a linear equation model developed was a good predictor ofV0 for the group.The study concluded that in situation where sophisticated equipments are lacking, this equation might be useful during exercise supervision for patients withCHF. [VO2 (ml kg-1 min-1) = 0.0105 x distance (m) + 0.0238 age (yr) - 0.03085 weight (kg) + 5.598]

Cardiovascular responses to treadmill exercise in Nigerian hypertensives with left ventricular hypertrophy

Background: Left ventricular hypertrophy (LVH) is an independent risk factor for adverse cardiac outcomes in hypertensive patients.Objective: This study is designed to assess the cardiovascular responses to treadmill exercise among Nigerian hypertensives with echocardiographically proven LVH.Materials and Methods: Fifty hypertensive patients with LVH (27 males and 23 females) between 30 and 65 years of age were studied in Nigeria. 50 hypertensive patients without LVH and 50 normal subjects who were age and sex matched served as controls. All patients and control subjects underwent M-mode, 2-D and Doppler ECHO-studies and the Bruce protocol treadmill exercise test.Results: The study showed that the estimated maximal oxygen consumption (MVO2) in MET reduced progressively from 8.39 &#177; 1.26 (normotensive control) to 7.62 &#177; 1.33 (hypertensive without LVH), 6.27 &#177; 0.99 (hypertensive with LVH) (P&lt;0.0001ANOVA). The duration of exercise (s) was also reduced in that order from 455.4 &#177; 79.1 to 411.6 &#177;8 2.3, 315.8 &#177; 75.6 respectively (P&lt;0.0001). The systolic blood pressure (SBP) and pressure rate product (PRP) during maximal exercise were also increased in hypertensives with LVH and hypertensive without LVH when compared to normotensive controls. The hypertensives with LVH and hypertensives without LVH also showed significant limitation to heart rate increase with exercise compared to normotensive controls (P&lt;0.003).Conclusion: This study demonstrated significant impairment of exercise capacity in hypertensives with or without LVH compared to normotensive subjects. Both earlier recognition and improved understanding of LVH may lead to more effective therapeutic strategies for this cardiovascular risk factor

Gender differences in the variables of exercise treadmill test in type 2 diabetes mellitus

Background: Exercise capacity, like some other variables of exercise stress test, is a strong predictor of cardiovascular and overall mortality. Many confounding factors, including gender, have been found to affect exercise capacity. This study evaluated whether exercise capacity differs in age-matched type 2 diabetic Nigerian men and their women counterparts and the hemodynamic variables of exercise treadmill test that correlate with exercise capacity in them.Materials and Methods: A total of 61 type 2 diabetics (male = 34; female = 27) aged 30 to 60 years who were recruited through the Medical Out-patient Department of OAUTHC, Ile Ife, Nigeria, underwent symptom- limited maximal treadmill exercise using Bruce protocol.Result: Patients had comparable clinical and demographic patterns. There was no gender difference in the chronotropic response to exercise. Males had faster heart rate recovery (HRR) than females. Though both sexes had similar resting systolic blood pressure (SBP), males had significantly higher peak SBP than females (216.2 &plusmn; 23.7 mmHg vs 203.3 &plusmn; 21.7 mmHg; P = 0.03). Exercise capacity was significantly higher in males (7.5 &plusmn; 2.0 METs) than females (6.4 &plusmn; 1.5 METs); P = 0.01. Significant correlates of exercise capacity in both sexes were fasting plasma glucose, resting diastolic blood pressure, Duke Treadmill Score, and HRR. Majority of the patients were in moderate DUKE risk subgroup and there was no statistically significant difference between males and females in this regard.Conclusion: Gender difference occurs in the exercise capacity of diabetic patients and the factors associated with this disparity may be related to gender differences in resting heart rate and HRR, both reflecting a withdrawal of vagal tone

Shifting trends in the pharmacologic treatment of hypertension in a Nigerian tertiary hospital: a real-world evaluation of the efficacy, safety, rationality and pharmaco-economics of old and newer antihypertensive drugs.

The current prescription patterns for essential hypertension and the efficacy, safety, tolerability and cost-effectiveness of the newer antihypertensive drugs were evaluated in Nigerian patients. The findings were compared with that of a previous study conducted in the same tertiary hospital 10 years earlier. A cross-sectional evaluation of blood pressure (BP) control in a hypertension clinic was undertaken among 150 Nigerian patients aged 61 +/- 12 years (55% females), with a duration of treatment on a particular drug class or combination of 9 +/- 3 months. The initial blood pressure was 176 +/- 20/108 +/- 11 mmHg and 22% of the patient had concurrent diabetes mellitus. Thiazide diuretics (D) alone or in combination remained the most commonly prescribed drugs in 56% of all patients. There were significant increases in the prescriptions of calcium channel blockers (CCBs) (51%), P < 0.0001, and ACE-inhibitors (ACEIs) (24%), P < 0.0001, but a slight reduction in the use of methyldopa, and fixed drug combinations (P < 0.01) compared to the previous study. The fall in systolic blood pressure on D (r = 0.65, P < 0.001) or CCB (r = 0.48, P < 0.02) was significantly correlated with the initial systolic blood pressure, but not age. More patients achieved normotension BP < 140/90 mmHg on CCB monotherapy (71%), than D monotherapy (56%). Combination therapy with ACEIs + D or methyldopa+thiazides normalized BP in 63 and 68%, respectively. Pulse pressure, a surrogate marker for cardiovascular complications and mortality in essential hypertension, was significantly reduced (P < 0.01) equally by all treatments, with 95% confidence intervals ranging from -28 to -1 mmHg. However, hypertensive-diabetic (HT-DM) patients (n = 33) exhibited no significant change in pulse pressure in response to treatment. Adverse drug reactions that occurred in 11% were impotence or postural dizziness with D, headache and pitting oedema with CCB, and dry cough with ACEI. Pharmaco-economic comparison of the drug classes revealed that for every US dollar (dollar) spent per month, the percentage of treated patients attaining normotension was 18.6 for D, 4.73 for CCB, 3.5 for ACEI + D and 13.6 for methyldopa + thiazides. A combination of ACEI + CCB or D was the preferred treatment for hypertensive-diabetic Nigerians, but only 24% attained a BP < 130/85 mmHg. These results demonstrate a shift in trend to a more rational and efficacious treatment of hypertension over a 10 year period. This may be associated, at least in part, with the intensive and continuous education of the prescribers in rational drug use and the introduction of a hospital formulary. Methyldopa is still a highly efficacious and cost-effective drug in this population. Black HT-DM Africans still constitute a subgroup who not only require more and costlier antihypertensive drugs, but whose BP control is suboptimal, and exhibit a poor therapeutic response to other risk factors (pulse pressure) that constitute a continuing risk for cardiovascular mortality

Prognostic indices among hypertensive heart failure patients in Nigeria: the roles of 24-hour Holter electrocardiography and 6-minute walk test

Tuoyo O Mene-Afejuku,1,2 Michael O Balogun,2 Anthony O Akintomide,2 Rasaaq A Adebayo2 1Department of Medicine, Metropolitan Hospital Center, New York, NY, USA; 2Cardiology Unit, Department of Medicine, Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Osun State, Nigeria Background: Hypertensive heart failure (HHF) is associated with a poor prognosis. There is paucity of data in Nigeria on prognosis among HHF patients elucidating the role of 24-hour Holter electrocardiogram (ECG) in concert with other risk factors.Objective: The aim of this study was to determine the prognostic utility of 24-hour Holter ECG, the 6-minute walk test (6-MWT), echocardiography, clinical and laboratory parameters among HHF patients.Methods: A total of 113 HHF patients were recruited and followed up for 6&nbsp;months. Thirteen of these patients were lost to follow-up, and as a result only 100 HHF patients were analyzed. All the patients underwent baseline laboratory tests, echocardiography, 24-hour Holter ECG and the 6-MWT. HHF patients were analyzed as &ldquo;mortality vs alive&rdquo; and as &ldquo;events vs no-events&rdquo; based on the outcome at the end of 6&nbsp;months. Events was defined as HHF patients who were rehospitalized for heart failure (HF), had prolonged hospital stay or died. No-events group was defined as HHF patients who did not meet the criteria for the events group.Results: HHF patients in the mortality group (n = 7) had significantly higher serum urea (5.71 &plusmn; 2.07 mmol/L vs 3.93 &plusmn; 1.45 mmol/L, p = 0.003) than that in those alive. After logistic regression, high serum urea conferred increased mortality risk (p = 0.035). Significant premature ventricular complexes (PVCs) on 24-hour Holter ECG following logistic regression were also significantly higher (p&nbsp;= 0.015) in the mortality group than in the &ldquo;alive&rdquo; group (n = 93) at the end of the 6-month follow-up period. The 6-minute walk distance (6-MWD) was least among the HHF patients who died (167.26&nbsp;m &plusmn; 85.24&nbsp;m). However, following logistic regression, the 6-MWT was not significant (p = 0.777) for predicting adverse outcomes among HHF patients. Patients in the events group (n = 41) had significantly higher New York Heart Association (NYHA) class (p = 0.001), Holter-detected ventricular tachycardia (VT; p = 0.009), Holter-detected atrial fibrillation (AF; p = 0.028) and PVCs (p = 0.017) following logistic regression than those in the no-events group (n = 59).Conclusion: High NYHA class, elevated serum urea, Holter ECG-detected AF and ventricular arrhythmias are predictive of a poor outcome among HHF patients. The 6-MWT was not a useful prognostic index in this study. Keywords: hypertensive heart failure, ventricular tachycardia, Holter electrocardiography, prognosi

Compliance of Radiation Dose and Image Quality in a Nigerian Teaching Hospital with the European Guidelines for Pediatric Screen-Film Chest Radiography

Introduction Blue light is a part of the spectrum with the highest energy content, which can reach the retina. The damage that it can cause to the retina is called photochemical or blue-light retinal injury. For the retinal injury assessment of the photochemical and aphakic retinal hazards in the wavelength range of 300-700 nm, use of effective spectral radiance limits (W.m-2.sr-1) seems to be slightly perplexing for ophthalmologists. However, in this study, the temperature (OC) that can emit the same effective spectral radiance limit was detected using a computer code; this method could help prevent blue-light retinal injury. Materials and Methods The limits proposed by International Commission on Non-Ionizing Radiation Protection for blue-light induced photochemical and aphakic eye hazards were expressed in terms of temperature by a computer code for 13 Planckian sources that produce the same radiance. The calculated temperature by the computer code, here known as threshold temperature, is the maximum source temperature that for a specified viewing distance and source diameter does not cause the exposure at the receptor position to exceed the exposure limit. Results In terms of threshold temperature, the exposure limits for aphakia or infant retinal injury are much lower than retinal photochemical damage. For light sources with more effective radiances, these differences reach 800 K. Conclusion This method allows evaluation of photochemical and aphakic retinal hazard only by comparing the calculated threshold temperature by a computer code with the temperature of the radiant source, which may be beneficial for hygienist and ophthalmic clinicians

Which factors actually influence the development and progression of overt nephrophathy in Nigerian diabetics

No Abstract Supplie