Olufemi E. Ajayi

Two dimensional and Doppler echocardiographic evaluation of patients presenting at Obafemi Awolowo University Teaching Hospitals Complex Ile Ife Nigeria a prospective study of 2501 subjects

Background Echocardiography remains a key noninvasive cardiac investigative tool in the management of patients, especially in a developing economy like Nigeria. In this study, we investigated the indications for transthoracic echocardiography and spectrum of cardiac disease found in patients referred to our cardiac unit for echocardiography. Methods A prospective two-dimensional, pulsed, continuous, and color-flow Doppler echocardiographic evaluation was done using the transthoracic approach in 2501 patients over an eight-year period. Univariate data analysis was performed for mean age, gender, clinical indications, and diagnoses. Results The subject age range was less than 12 months to 97 years (mean 52.39 years). There were 1352 (54.06%) males and 1149 (45.94%) females. The most common indication for echocardiography was hypertension (52.1%) followed by congestive cardiac failure (13.9%). Others were for screening (6.1%), arrhythmias (5%), cerebrovascular disease (5%), chest pain (3.3%), chronic kidney disease (3.2%), congenital heart disease (2.6%), cardiomyopathy (1.8%), rheumatic heart disease (1.7%), diabetes mellitus (1.3%), thyrocardiac disease (1.2%), ischemic heart disease (1.2%), and pericardial disease (1.1%). The echocardiographic diagnosis was hypertensive heart disease in 59.4% of subjects and normal in 14.1%. Other echocardiographic diagnoses included rheumatic heart disease (3.1%), congenital heart disease (2.1%), cardiomyopathy (1.7%), pericardial disease (1.1%), and ischemic heart disease (0.1%). Conclusion Hypertension and its cardiac complications is the most common echocardiographic indication and diagnosis at our unit.

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 ± 1.26 (normotensive control) to 7.62 ± 1.33 (hypertensive without LVH), 6.27 ± 0.99 (hypertensive with LVH) (P<0.0001ANOVA). The duration of exercise (s) was also reduced in that order from 455.4 ± 79.1 to 411.6 ±8 2.3, 315.8 ± 75.6 respectively (P<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<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.

Ambulatory blood pressure profile and left ventricular geometry in Nigerian hypertensives.

Background: Left ventricular hypertrophy (LVH) is an independent cardiac risk factor in hypertensives and the structural classification of left ventricular (LV) geometry provides additional prognostic information. Ambulatory blood pressure (ABP) monitoring has been shown to be superior to office blood pressure (BP) in relation to hypertension LVH. We investigated ambulatory BP variables in relation to LV geometric patterns in Nigerian hypertensives. Materials and Methods: A total of 130 patients (males = 96, females = 34) with hypertension had their 24-hours ambulatory BP and trans-thoracic 2D/M- mode echocardiography. Data were analyzed with SPSS 13.0. P < 0.05 was considered statistically significant. Results: The mean age of the patients was 54.08±11.88 years. The prevalence rate of abnormal LV geometry was 48.4%. Mean ambulatory Systolic BP (day time, night time and 24-hour-average) was significantly higher in patients with LVH compared with those without LVH. Day-night systolic and diastolic BP decay (i.e. percentage nocturnal decline in BP) was also significantly lower in LVH group than in the group without LVH. Patients with eccentric LVH had abnormal day time mean ambulatory systolic BP, night time mean ambulatory systolic BP, elevated day time and night time systolic BP loads, as well as non-dipping diastolic BP pattern. Significant correlates of LV mass index in this study population were mean ambulatory systolic BP (day time: r = 0.355, P = 0.004; night time: r = 0.343, P = 0.005; 24- hour average: r = 0.358, P = 0.004) and day-night decay (systolic: r = -0.388, P = 0.007; diastolic: r = -0.290, P = 0.022) as well as 24-hour systolic BP variability. Conclusion: The presence of LVH in hypertension was associated with higher mean ambulatory systolic BP and lower percentage nocturnal decline in systolic and diastolic BP than its absence which appeared to be worse in patients with eccentric LV geometry when compared with other geometric patterns.

Heart rate variability and arrhythmic patterns of 24-hour Holter electrocardiography among Nigerians with cardiovascular diseases

Background Facilities for Holter electrocardiography (ECG) monitoring in many Nigerian hospitals are limited. There are few published works in Nigeria on the use of 24-hour Holter ECG in cardiac arrhythmic evaluation of patients with cardiovascular diseases. Objective To study the clinical indications, arrhythmic pattern, and heart rate variability (HRV) among subjects referred for 24-hour Holter ECG at our Cardiac Care Unit. Methods Three-hundred and ten patients (134 males and 176 females) were studied consecutively over a 48-month period using Schiller type (MT-101) Holter ECG machine. Results Out of the 310 patients reviewed, 134 were males (43.2%) and 176 were females (56.8%). The commonest indication for Holter ECG was palpitation followed by syncope in 71 (23%) and 49 (15.8%) of subjects, respectively. Premature ventricular complex and premature atrial complex were the commonest types of arrhythmia in 51.5% and 15% subjects, respectively. Ventricular arrhythmia was more prevalent in dilated cardiomyopathy patients (85.7%). The HRV of subjects with palpitation, stroke, and diabetes mellitus with autonomic neuropathy, using standard deviation of normal to normal intervals average (milliseconds), were 107.32±49.61, 79.15±49.15, and 66.50±15.54, respectively. The HRV, using standard deviation of averages of normal to normal intervals average (milliseconds), of patients with palpitation, stroke, and diabetes mellitus with autonomic neuropathy were 77.39±62.34, 57.82±37.05, and 55.50±12.71, respectively. Conclusion Palpitation and syncope were the commonest indications for Holter ECG among our subjects. The commonest arrhythmic patterns were premature ventricular complex and premature atrial complex, with ventricular arrhythmia being more prevalent in dilated cardiomyopathy. There was a reduction in HRV in patients with stroke and diabetic autonomic neuropathy.

Pattern of arrhythmias among Nigerians with congestive heart failure

Background In patients with heart failure, death is often sudden due to life-threatening arrhythmias. This work was carried out to evaluate the pattern of arrhythmias in Nigerians with heart failure. Materials and methods Thirty subjects with congestive heart failure (CHF), 30 subjects with hypertensive heart disease, and 15 normal subjects with no obvious features of heart disease were evaluated with resting and 24-hour electrocardiographic monitoring and transthoracic echocardiography. Data were analyzed with one-way analysis of variance with post hoc Duncan’s analysis, Fisher’s exact test, and linear regression analysis using SPSS version 16. Results CHF subjects had more instances of supraventricular tachycardia (P=0.005), ventricular extrasystoles (P<0.001), bigeminy (P<0.001), trigeminy (P<0.001), couplets (P<0.001), triplets (P<0.001), and nonsustained ventricular tachycardia (VT) (P=0.003) than the other two control groups. They also showed a significantly longer VT duration (4.6±5.6 seconds) compared with the other groups (P<0.001). Linear regression analysis showed a significant direct relationship between VT and the maximum number of ventricular extrasystoles per hour (P=0.001). Conclusion Cardiac arrhythmias are common in subjects with CHF and are more frequent when compared with patients with hypertensive heart disease and normal subjects.

Evaluation of the indications and arrhythmic patterns of 24 hour Holter electrocardiography among hypertensive and diabetic patients seen at OAUTHC, Ile-Ife Nigeria

Background There are very limited published studies in Nigeria on the use of 24 hour Holter electrocardiogram (Holter ECG) in the arrhythmic evaluation of hypertensive and diabetic patients. Objective To evaluate indications, arrhythmic pattern of Holter ECG, and heart rate variability (HRV) among patients with hypertensive heart disease (HHD) with or without heart failure and type 2 diabetes mellitus (T2DM) seen in our cardiac care unit. Methods Seventy-nine patients (32 males and 47 females) were studied consecutively over a year using Schiller type (MT-101) Holter ECG machine. Results Out of the 79 patients, 17 (21.5%) had HHD without heart failure, 33 (41.8%) had HHD with hypertensive heart failure (HHF), while 29 (36.7%) were T2DM patients. The mean (standard deviation) ages of HHD without heart failure, HHF and T2DM patients were 59.65 (±14.38), 65.15 (±14.30), and 54.66 (±8.88) respectively. The commonest indication for Holter ECG was palpitation (38%), followed by syncope (20.3%). Premature ventricular contraction was the commonest arrhythmic pattern among the 79 patients, especially among HHF patients. The HRV using standard deviation of all normal-normal intervals was significantly reduced in T2DM patients (81.03±26.33, confidence interval [CI] =71.02–91.05) compared to the HHD without heart failure (119.65±29.86, CI =104.30–135.00) and HHF (107.03±62.50, CI =84.00–129.19). There was a negative correlation between the duration of T2DM and HRV (r=−0.613). Conclusion Palpitation was the commonest Holter ECG indication and premature ventricular contractions were the commonest arrhythmic pattern among our patients. HRV was reduced in T2DM patients compared with hypertensive patients.

Valvular Regurgitation Impact on Left Ventricular 2-Dimensional and Doppler Echocardiographic Indices in Patients With Essential Hypertension

BACKGROUND Blacks have both a higher hypertension prevalence and accelerated cardiac end organ damage. Because blacks also have a higher prevalence of valvular heart disease, which occurs at a younger age than for whites, we further examined the contribution of valvular regurgitation to the severity of hypertensive heart disease in Nigerians. METHODS We evaluated and compared echocardiographic indexes in 75 essential hypertensive Nigerians with (n=48) and without (n=27) valvular regurgitations. Demographic and echocardiographic indices, as well as the types and severity of valvular lesions were compared between the groups using bivariate logistic regression and analysis of variance. RESULTS The 2 groups were of similar demographics, but those with regurgitations had larger cardiac size (p < .05), greater mass (147 +/- 31 vs. 122 +/- 32 g/m2, p = .01) higher volume (p < .01), and left atrial size (35.6 +/- 4.6 vs. 33.3 +/- 4.6 mm, p < .05). Atrial size, cardiac volume, and dimension were independent correlates/predictors of regurgitation occurrence. Relative wall thickness of at least 0.6 was more common in regurgitation patients. Cardiac mass was correlated to increasing age (r = 0.23, p = .043). The valvular lesions frequencies were aortic regurgitation, 8; mitral regurgitation, 22; and mixed, 18. The aortic orifice dimension was significantly different among the regurgitant cases, highest in aortic regurgitation (p = .001). Aortic orifice dimension increased with hypertension duration (p = .028). CONCLUSIONS Regurgitant lesions are common and occur early in hypertensive Africans. Apparently mild valvular regurgitation may accentuate preclinical concentric hypertrophy in hypertensive blacks.

Right ventricular systolic function in hypertensive heart failure

Background Heart failure (HF) is a major cause of cardiovascular admissions and hypertensive heart failure (HHF) is the most common cause of HF admissions in sub-Saharan Africa, Nigeria inclusive. Right ventricular (RV) dysfunction is being increasingly recognized in HF and found to be an independent predictor of adverse outcomes in HF. This study aimed to determine the prevalence of RV systolic dysfunction in HHF by several echocardiographic parameters. Methodology One hundred subjects with HHF were recruited consecutively into the study along with 50 age and sex-matched controls. All study participants gave written informed consent, and had a full physical examination, blood investigations, 12-lead electrocardiogram, and transthoracic echocardiography. RV systolic function was assessed in all subjects using different methods based on the American Society of Echocardiography guidelines for echocardiographic assessment of the right heart in adults. This included tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (MPI), and RV systolic excursion velocity by tissue Doppler (S′). Results RV systolic dysfunction was found in 53% of subjects with HHF by TAPSE, 56% by RV MPI, and 48% by tissue Doppler systolic excursion S′. RV systolic dysfunction increased with reducing left ventricular ejection fraction (LVEF) in subjects with HHF. Conclusion A high proportion of subjects with HHF were found to have RV systolic functional abnormalities using TAPSE, RV MPI, and RV S′. Prevalence of RV systolic dysfunction increased with reducing LVEF.

The "Obesity Paradox" in Nigerians with heart failure

BACKGROUND Previous studies have suggested that a high body mass index (BMI) was associated with improved outcome in congestive heart failure (CHF). The aim of this study was to examine the relationship between BMI and echocardiographic variables of cardiac function in stable outpatients with heart failure. METHODS AND MATERIALS This is a cross-sectional study in which the cardiology clinic out-patients of Obafemi Awolowo University Teaching Hospital with heart failure were recruited. Patients were categorized using baseline BMI as normal weight BMI = 18.5-24.9 kg/m(2) and overweight/obese (BMI > 25.0 kg/m(2)). Risks associated with BMI groups were evaluated and the data were analyzed with the aid of SPSS 15.0 software. RESULTS Patients with higher BMI have higher left ventricular ejection fraction and fractional shortening and lesser tendency to have an abnormal left ventricular geometry and better functional (New York Heart Association) class of heart failure at presentation. CONCLUSION Overweight and obese patients had less severe degree of heart failure than normal weight patients and efforts should be made to prevent excessive weight loss in patients with heart failure.

Clinical and Echocardiographic Predictors of Arrhythmias Detected With 24-Hour Holter Electrocardiography Among Hypertensive Heart Failure Patients in Nigeria:

Background: Hypertensive heart failure (HHF) is the commonest form of heart failure in Nigeria. There is paucity of data in Nigeria on 24-hour Holter electrocardiography (24-HHECG) and important predictors of arrhythmias among HHF patients. Objectives: To determine the 24-HHECG characteristics among HHF patients. To determine the clinical and echocardiographic predictors of arrhythmias detected using 24-HHECG among HHF patients. Methods: A total of 100 HHF patients as well as 50 age-matched and sex-matched apparently healthy controls were prospectively recruited over a period of 1 year. They all had baseline laboratory tests, echocardiography, and 24-HHECG. Results: Hypertensive heart failure patients had significantly higher counts of premature ventricular contractions (PVCs) than the controls (P ≤ .001). Ventricular tachycardia (VT) was recorded in 29% of HHF patients as compared with controls who had no VT on 24-HHECG. The standard deviation of all normal to normal sinus RR intervals over 24 hours (SDNN) was abnormally reduced among HHF patients when compared with controls (P = .046). There was positive correlation between atrial fibrillation (AF) and the following parameters: PVCs (r = .229, P = .015), New York Heart Association (NYHA) (r = .196, P = .033), and VT (r = .223, P = .018). Following multiple linear regression, left ventricular ejection fraction (LVEF) (P ≤ .001) and serum urea (P = .037) were predictors of PVCs among HHF patients. Serum creatinine (P ≤ .001), elevated systolic blood pressure (SBP) (P = .005), and PVCs (P ≤ .001) were important predictors of VT among HHF patients. Conclusions: Renal dysfunction and reduced LVEF were important predictors of ventricular arrhythmias. High counts of PVCs and elevated SBP were predictive of the occurrence of VT among HHF patients. The NYHA class and ventricular arrhythmias have a significant positive correlation with AF. The SDNN is reduced in HHF patients.