Registry for Acute Coronary Events in Nigeria (RACE-Nigeria): Clinical Characterization, Management, and Outcome.

Background Coronary artery disease was hitherto a rarity in Africa. Acute coronary syndrome (ACS) accounts for coronary artery disease-related morbidity and mortality. Reports on ACS in Africa are few. Methods and Results We enrolled 1072 indigenous Nigerian people 59.2±12.4 years old (men, 66.8%) with ACS in an observational multicentered national registry (2013-2018). Outcome measures included incidence, intervention times, reperfusion rates, and 1-year mortality. The incidence of ACS was 59.1 people per 100 000 hospitalized adults per year, and comprised ST-segment-elevation myocardial infarction (48.7%), non-ST-segment-elevation myocardial infarction (24.5%), and unstable angina (26.8%). ACS frequency peaked 10 years earlier in men than women. Patients were predominantly from urban settings (87.3%). Median time from onset of symptoms to first medical contact (patients with ST-segment-elevation myocardial infarction) was 6 hours (interquartile range, 20.1 hours), and only 11.9% presented within a 12-hour time window. Traditional risk factors of coronary artery disease were observed. The coronary angiography rate was 42.4%. Reperfusion therapies included thrombolysis (17.1%), percutaneous coronary intervention (28.6%), and coronary artery bypass graft (11.2%). Guideline-based pharmacotherapy was adequate. Major adverse cardiac events were 30.8%, and in-hospital mortality was 8.1%. Mortality rates at 30 days, 3 months, 6 months, and 1 year were 8.7%, 9.9%, 10.9%, and 13.3%, respectively. Predictors of mortality included resuscitated cardiac arrest (odds ratio [OR], 50.0; 95% CI, 0.010-0.081), nonreperfusion (OR, 34.5; 95% CI, 0.004-0.221), pulmonary edema (OR, 11.1; 95% CI, 0.020-0.363), left ventricular diastolic dysfunction (OR, 4.1; 95% CI, 0.091-0.570), and left ventricular systolic dysfunction (OR, 2.1; 95% CI, 1.302-3.367). Conclusions ACS burden is rising in Nigeria, and patients are relatively young and from an urban setting. The system of care is evolving and is characterized by lack of capacity and low patient eligibility for reperfusion. We recommend preventive strategies and health care infrastructure-appropriate management guidelines.

Hypertensive heart failure in Nigerian Africans: insights from the Abeokuta Heart Failure Registry.

Data from the Abeokuta Heart Failure Registry were used to determine the clinical characteristics, mode of treatment, and short- and medium-term outcomes of patients with hypertensive heart failure. A total of 320 patients were consecutively studied, comprising 184 men (57.5%) and 136 women (42.5%) aged 58.4±12.4 and 60.6±14.5 years, respectively. Most patients (80%) presented with New York Heart Association functional class III or IV and around one third (35%) had preserved systolic function. Median hospital stay was 9 days (interquartile range 5-21) while intra-hospital mortality was 3.4%. The 30-day, 90-day, and 180-day mortality rates were 0.9% (95% confidence interval, -0.2 to 3.5), 3.5% (95% confidence interval, -1.7 to 7.3), and 11.7% (95% confidence interval, -7.8 to 17.5), respectively. In a multiple logistic regression analysis, only serum creatinine was an independent predictor of mortality at 180 days (adjusted odds ratio, 1.76; 95% confidence interval, -1.17 to 2.64). Hypertension is the most common etiological risk factor for heart failure in Nigeria. Most patients present in the fourth decade of life with severe heart failure and secondary valvular dysfunction and significant in-hospital mortality.

Economic burden of heart failure: investigating outpatient and inpatient costs in Abeokuta, Southwest Nigeria.

BACKGROUND: Heart failure (HF) is a deadly, disabling and often costly syndrome world-wide. Unfortunately, there is a paucity of data describing its economic impact in sub Saharan Africa; a region in which the number of relatively younger cases will inevitably rise. METHODS: Heath economic data were extracted from a prospective HF registry in a tertiary hospital situated in Abeokuta, southwest Nigeria. Outpatient and inpatient costs were computed from a representative cohort of 239 HF cases including personnel, diagnostic and treatment resources used for their management over a 12-month period. Indirect costs were also calculated. The annual cost per person was then calculated. RESULTS: Mean age of the cohort was 58.0 ± 15.1 years and 53.1% were men. The total computed cost of care of HF in Abeokuta was 76, 288,845 Nigerian Naira (US$508, 595) translating to 319,200 Naira (US$2,128 US Dollars) per patient per year. The total cost of in-patient care (46% of total health care expenditure) was estimated as 34,996,477 Naira (about 301,230 US dollars). This comprised of 17,899,977 Naira- 50.9% ($US114,600) and 17,806,500 naira -49.1%($US118,710) for direct and in-direct costs respectively. Out-patient cost was estimated as 41,292,368 Naira ($US 275,282). The relatively high cost of outpatient care was largely due to cost of transportation for monthly follow up visits. Payments were mostly made through out-of-pocket spending. CONCLUSION: The economic burden of HF in Nigeria is particularly high considering, the relatively young age of affected cases, a minimum wage of 18,000 Naira ($US120) per month and considerable component of out-of-pocket spending for those affected. Health reforms designed to mitigate the individual to societal burden imposed by the syndrome are required.

Short-term outcomes after hospital discharge in patients admitted with heart failure in Abeokuta, Nigeria: data from the Abeokuta Heart Failure Registry.

BACKGROUND: Compared to other regions of the world, there is a paucity of data on the short-term outcome of acute heart failure (AHF) in Africa's most populous country, Nigeria. We examined the six-month outcomes (including case fatalities) in 285 of 309 AHF subjects admitted with HF to a tertiary hospital in Abeokuta, Nigeria. METHODS: The study cohort of 285 subjects comprised 150 men (52.6%) and 135 women (47.4%) with a mean age of 56.3 ± 15.6 years and the majority in NYHA class III (75%). RESULTS: There were a number of differences according to the subject's gender; men being older and more likely to present with hypertensive heart disease (with greater left ventricular mass) while also having greater systolic dysfunction. Mean length of stay was 10.5 ± 5.9 days. Mean follow up was 205 days, with 23 deaths and 20 lost to follow up. At 30 days, 4.2% (95% CI: 2.4-7.3%) had died and by 180 days this had increased to 7.5% (95% CI: 4.7-11.2%); with those subjects with pericardial disease demonstrating the highest initial mortality rate. Over the same period, 13.9% of the cohort was re-admitted at least once. CONCLUSIONS: The characteristics of this AHF cohort in Nigeria were different from those reported in high-income countries. Cases were relatively younger and presented with non-ischaemic aetiological risk factors for HF, especially hypertensive heart disease. Moreover, mortality and re-admission rates were relatively lower, suggesting region-specific strategies are required to improve health outcomes.

Predictors of rehospitalization in patients admitted with heart failure in Abeokuta, Nigeria: data from the Abeokuta heart failure registry.

OBJECTIVE: We sought, for the first time, to examine the rate and predictors of hospital readmission in patients discharged after an episode of heart failure (HF) in Nigeria. METHODS: This was a hospital-based, prospective, observational study that used the data from the Abeokuta HF Registry. RESULTS: Overall, 1.53% (95% confidence interval [CI] 0.58-4.02) and 12.2% (95% CI 8.88-16.8) of patients were re-hospitalized at least once within 30 days and 6 months, respectively (5.3% had multiple readmissions); the latter comprised 21/138 men (15.2%) and 11/124 (8.9%) women. A total of 11 (4.2%) died (all of whom had been rehospitalized). Worsening HF (24 cases, 75%) was the commonest reason for readmission. Among others, factors associated with rehospitalization included presence of mitral regurgitation (odds ratio [OR] 2.37, 95% CI 1.26-4.46), age ≥ 60 years (OR 2.04, 95% CI 0.96-3.29), presence of tricuspid regurgitation (OR 1.77, 95% CI 0.86-3.61), and presence of atrial fibrillation (OR 1.34, 95% CI 0.59-3.03). However, on an adjusted basis, only female sex (adjusted OR 0.33, 95% CI 0.14-0.79; P = .014 vs male) and body mass index <19 kg/m² (adjusted OR 3.74, 95% CI 1.15-12.16; P = .028 vs ≥ 19 kg/m²) were independent correlates of readmission during 6 months' follow-up. CONCLUSIONS: HF rehospitalization within 6 months' follow-up occurred in ∼12% of our cohort living an environment where HF etiology is predominately nonischemic and the HF population is relatively younger. Higher rates of readmission were noted in those with older age, lower body mass index, low literacy, lower serum sodium level, and presence of atrial fibrillation, renal dysfunction, and valvular dysfunction.

Contemporary profile of acute heart failure in Southern Nigeria: data from the Abeokuta Heart Failure Clinical Registry.

OBJECTIVES: The aim of this study was to determine the contemporary profile, clinical characteristics, and intrahospital outcomes of acute heart failure (AHF) in an African urban community. BACKGROUND: There are limited data on the current burden and characteristics of AHF in Nigerian Africans. METHODS: Comprehensive and detailed clinical and sociodemographic data were prospectively collected from 452 consecutive patients presenting with AHF to the only tertiary hospital in Abeokuta, Nigeria (population about 1 million) over a 2-year period. RESULTS: The mean age was 56.6 ± 15.3 years (57.3 ± 13.4 years for men, 55.7 ± 17.1 years for women), and 204 patients (45.1%) were women. Overall, 415 subjects (91.8%) presented with de novo AHF. The most common risk factor for heart failure was hypertension (pre-existing in 64.3% of patients). Type 2 diabetes mellitus was present in 41 patients (10.0%). Hypertensive heart failure was the most common etiological cause of heart failure, responsible for 78.5% of cases. Dilated cardiomyopathy (7.5%), cor pulmonale (4.4%), pericardial disease (3.3%), rheumatic heart disease (2.4%), and ischemic heart disease were less common (0.4%) causes. The majority of subjects (71.2%) presented with left ventricular dysfunction (mean left ventricular ejection fraction 43.9 ± 9.0%), with valvular dysfunction and abnormal left ventricular geometry frequently documented. The mean duration of hospital stay was 11.4 ± 9.1 days, and intrahospital mortality was 3.8%. CONCLUSIONS: Compared with those in high-income countries, patients presenting with AHF in Abeokuta, Nigeria, are relatively younger and still of working age. It is also more common in men and associated with severe symptoms because of late presentation. Intrahospital mortality is similar to that in other parts of the world.

Republished: recent advances in the epidemiology, diagnosis and treatment of endomyocardial fibrosis in Africa.

Endomyocardial fibrosis (EMF) continues to be an important and disabling disease in many parts of Africa, although its prevalence has declined in some parts of the continent. Increased access to medical care in general and increased availability of echocardiography in some parts of the continent have led to recognition of the disease in areas in which the disease had not been previously reported, and this has given new insights into its natural history. However, the early manifestations of EMF continue to elude clinicians and researchers, and no progress has been made in defining its aetiology. Advances have, however, been made in establishing the epidemiology and improving clinical diagnosis and management, through modern medical therapy and improved surgical techniques. Research is still required to define clinical, biological and echocardiographic markers of early stages of EMF, so that advances in the knowledge of its pathogenesis and pathophysiology can be made. This will hopefully determine preventive measures and avoid the burden of this debilitating condition in this continent.

Non-invasive estimation of pulmonary artery pressures in patients with sickle cell anaemia in Ibadan, Nigeria: an echocardiographic study.

INTRODUCTION: Pulmonary hypertension is emerging as one of the causes of morbidity and mortality in adults with sickle cell disease. The prevalence of pulmonary hypertension in Nigerian adults with sickle cell anaemia is unknown. We decided to estimate the pulmonary artery systolic and diastolic pressures in subjects with sickle cell anaemia seen at the University College Hospital, Ibadan, Nigeria, and to determine the frequency of pulmonary hypertension among them. METHODS: Ninety patients (38 males and 52 females) with sickle cell anaemia in steady state and comparable age- and sex-matched normal controls had a clinical evaluation and echocardiographic examination. RESULTS: The mean age of the subjects with sickle cell anaemia was 24.0 (9.00) years while the mean age for the control group was 24.0 (7.00) years. The frequency of pulmonary hypertension as assessed by a tricuspid regurgitant jet velocity of > 2.5 m/s in this study was 12.2%. Larger left ventricular dimensions and volumes, higher stroke volume and increased left ventricular mass indexed by body surface area were found to be associated with pulmonary hypertension. A multivariate analysis of the potential predictors of pulmonary hypertension in this study showed that male sex and lower packed cell volume (PCV) were independent predictors of pulmonary hypertension in patients with sickle cell anaemia. CONCLUSION: We conclude that pulmonary artery systolic and diastolic pressures are higher in subjects with sickle cell disease than normal controls. Male sex and low PCV are independent determinants of pulmonary arterial pressure in subjects with sickle cell anaemia in Nigeria.

Recent advances in the epidemiology, diagnosis and treatment of endomyocardial fibrosis in Africa.

Endomyocardial fibrosis (EMF) continues to be an important and disabling disease in many parts of Africa, although its prevalence has declined in some parts of the continent. Increased access to medical care in general and increased availability of echocardiography in some parts of the continent have led to recognition of the disease in areas in which the disease had not been previously reported, and this has given new insights into its natural history. However, the early manifestations of EMF continue to elude clinicians and researchers, and no progress has been made in defining its aetiology. Advances have, however, been made in establishing the epidemiology and improving clinical diagnosis and management, through modern medical therapy and improved surgical techniques. Research is still required to define clinical, biological and echocardiographic markers of early stages of EMF, so that advances in the knowledge of its pathogenesis and pathophysiology can be made. This will hopefully determine preventive measures and avoid the burden of this debilitating condition in this continent.

Relationship between 24-hour blood pressure pattern and left ventricular structure and function in hypertensive Nigerians.

OBJECTIVE: Blood pressure variation throughout the day is known to have cardiovascular consequences. Left ventricular (LV) mass is more closely related to 24-hour blood pressure than casual blood pressure. Daytime blood pressure expectedly is higher than that of nighttime under normal circumstances. The effect of 24-hour blood pressure pattern on the left ventricular structure and function has not been examined in hypertensive Nigerians. The aim of our study was to assess the 24-hour blood pressure pattern and its relationship to the LV structure and function in newly diagnosed hypertensives in Nigeria. We hypothesized that 24-hour blood pressure was more related to left ventricular structure than casual blood pressure in hypertensive Nigerians. DESIGN: Cross-sectional study. SETTING: The study was carried out at the Cardiology Unit of the Department of Medicine, University College Hospital, Ibadan, South West Nigeria. PARTICIPANTS: Three casual blood pressure measurements were taken, while the participants were resting, using standardized digital blood pressure machine. Mean of the 3 measurements was used to categorize the participants as hypertensives or normotensives (controls). A calibrated Schiller BR-102 ABPM machine was used to measure the 24-hour blood pressure in 210 hypertensives and 202 normotensives (controls). Daytime and nighttime systolic (SBP) and diastolic blood pressures (DBP) were acquired every 20 minutes. Left ventricular mass was indexed by the allometric power of height (height 2.7) and left ventricular hypertrophy was considered present if LVM was > or = 49.2 g/m2.7 in males or > or = 46.7 g/m2.7 in females. MAIN OUTCOMES: The hypertensives and the controls were comparable in their demographic characteristics. Among the hypertensives, mean casual blood pressure and mean 24-hour blood pressure (SD) were 165(16)/96(8) mm Hg and 132(22)/84(15) mm Hg, respectively (P < .0001). 24-hour, day- and nighttime blood pressure were statistically related to left ventricular mass and indexed left ventricular mass in the hypertensives (r = .40 and .40, respectively for mean 24-hour SBP; r = .34 and .30, respectively for mean 24-hour DBP; r =.33 and .35, respectively for mean nighttime SBP, and; r = .22 and .24, respectively for mean nighttime DBP. The relationship was significant for mean 24-hour blood pressures but not for mean nighttime blood pressures for normal controls. There was no significant correlation between 24-hour blood pressure and indices of left ventricular function. CONCLUSIONS: Our study has shown a stronger relationship between 24-hour mean blood pressure and left ventricular mass compared with casual blood pressure. However there is no statistical relationship between 24-hour blood pressure and indices of left ventricular systolic and diastolic function.

Blood pressure, prevalence of hypertension and hypertension related complications in Nigerian Africans: A review.

To review studies on hypertension in Nigeria over the past five decades in terms of prevalence, awareness and treatment and complications. Following our search on Pubmed, African Journals Online and the World Health Organization Global cardiovascular infobase, 1060 related references were identified out of which 43 were found to be relevant for this review. The overall prevalence of hypertension in Nigeria ranges from 8%-46.4% depending on the study target population, type of measurement and cut-off value used for defining hypertension. The prevalence is similar in men and women (7.9%-50.2% vs 3.5%-68.8%, respectively) and in the urban (8.1%-42.0%) and rural setting (13.5%-46.4%).The pooled prevalence increased from 8.6% from the only study during the period from 1970-1979 to 22.5% (2000-2011). Awareness, treatment and control of hypertension were generally low with attendant high burden of hypertension related complications. In order to improve outcomes of cardiovascular disease in Africans, public health education to improve awareness of hypertension is required. Further epidemiological studies on hypertension are required to adequately understand and characterize the impact of hypertension in society.

Plasma catecholamines in Nigerians with primary hypertension.

BACKGROUND: Hypertension is the most common cardiovascular disease worldwide and is a major cause of morbidity and mortality. Increased adrenergic activity is thought to play a major role in the initiation and progression of the hypertensive state. Hypertension is more severe in Blacks when compared with White patients. Much of the evidence for the increased adrenergic activity is from studies in predominantly White participants. This study aims to evaluate the adrenergic system in Black Nigerian hypertensives by measuring their plasma catecholamines. METHODS: Eighty-two newly diagnosed hypertensives and 51 normal controls were recruited for the study. Blood was obtained from the participants after an overnight fast. Also, a 24-hr urine collection was obtained. Levels of plasma noradrenaline, adrenaline, renin, angiotensin converting enzyme (ACE), atrial natriuretic peptide (ANP), aldosterone and insulin levels were determined using HPLC. Fasting plasma glucose was also determined. RESULTS: Plasma noradrenaline level was higher while plasma adrenaline level was lower in the hypertensives. The hypertensives also had lower levels of plasma renin, ACE, and ANP. Systolic blood pressure negatively correlated with plasma adrenaline (r = -0.29, P < .001) and positively correlated with plasma noradrenaline (r = 0.31, P < .001). Renin and ANP also correlated negatively with blood pressure (r = -0.22, P = .012 and r = -0.34, P < .0001 respectively). CONCLUSIONS: Black Nigerian hypertensives demonstrate elevated levels of plasma noradrenaline when compared with normal controls. This is consistent with the hypothesis of the hyperadrenergic state in hypertension. Further studies are needed to relate the hyperadrenergic state to the racial differences in the severity of hypertension.

Uncorrected tetralogy of fallot in a 25-year old nigerian african.

Tetralogy of Fallot is the most common form of cyanotic congenital heart disease. Survival after the age of 12 years without corrective surgery is rare. We present the case of a 25 year-old man with uncorrected tetralogy of Fallot. Possible reasons for the longetivity in this patient are left ventricular hypertrophy and systemic to pulmonary shunting through internal mammary arteries.

Characterisation of heart failure with normal ejection fraction in a tertiary hospital in Nigeria.

BACKGROUND: The study aimed to determine the frequency and characteristics of heart failure with normal EF in a native African population with heart failure. METHODS: It was a hospital cohort study. Subjects were 177 consecutive individuals with heart failure and ninety apparently normal control subjects. All the subjects underwent transthoracic echocardiography. The group with heart failure was further subdivided into heart failure with normal EF (EF > or = 50) (HFNEF) and heart failure with low EF(EF <50)(HFLEF). RESULTS: The subjects with heart failure have a mean age of 52.3 +/- 16.64 years vs 52.1 +/- 11.84 years in the control subjects; p = 0.914. Other baseline characteristics except blood pressure parameters and height were comparable between the group with heart failure and the control subjects. The frequency of HFNEF was 39.5%. Compared with the HFLEF group, the HFNEF group have a smaller left ventricular diameter (in diastole and systole): (5.2 +/- 1.22 cm vs 6.2 +/- 1.39 cm; p < 0.0001 and 3.6 +/- 1.24 cm vs 5.4 +/- 1.35 cm;p < 0.0001) respectively, a higher relative wall thickness and deceleration time of the early mitral inflow velocity: (0.4 +/- 0.12 vs 0.3 +/- 0.14 p < 0.0001 and 149.6 +/- 72.35 vs 110.9 +/- 63.40 p = 0.001) respectively. The two groups with heart failure differed significantly from the control subjects in virtually all echocardiographic measurements except aortic root diameter, LV posterior wall thickness(HFLEF), and late mitral inflow velocity(HFNEF). HFNEF accounted for 70(39.5%) of cases of heart failure in this study. Hypertension is the underlying cardiovascular disease in 134(75.7%) of the combined heart failure population, 58 (82.9%) of the subjects with HFNEF group and 76(71%) of the HFLEF group. Females accounted for 44 (62.9%) of the subjects with HFNEF against 42(39.3%) in the HFLEF group (p = 0.002). CONCLUSION: The frequency of heart failure with normal EF in this native African cohort with heart failure is comparable with the frequency in other populations. These groups of patients are more likely female, hypertensive with concentric pattern of left ventricular hypertrophy.

Left ventricular geometric patterns in normotensive type 2 diabetic patients in Nigeria: an echocardiographic study.

Left ventricular hypertrophy has been linked with diabetes mellitus and abnormal glucose tolerance in several studies. Most previous studies have been carried out in the western world with dearth of data in native Africans. A total of 122 type 2 diabetic patients with a mean age of 55.0+/-8.5 years and another 90 normal patients with a mean age of 55.4+/-8.7 years were recruited for the study. Two-dimensional guided M-mode echocardiography was performed on each patient. In the diabetic patients, 49.2% had normal geometry, 23.0% had concentric hypertrophy, 13.0% had concentric remodeling, and 14.8% had eccentric hypertrophy. In the control group, 72.2% had normal geometry, 4.4% had concentric hypertrophy, 11.2% had concentric remodeling, and 12.2% had eccentric hypertrophy. In a multiple regression analysis, there was significant difference in the geometric pattern of the diabetics and controls (chi(2)=11.09, P<.001). Diabetes mellitus is independently associated with left ventricular structural changes in Nigerian diabetics.

Characterisation of left ventricular function by tissue Doppler imaging technique in newly diagnosed, untreated hypertensive subjects.

BACKGROUND: Hypertension results in structural and functional changes in the heart. Early detection of abnormalities of cardiac structure and function is important in the assessment and treatment of hypertensive subjects. The aim of this study was to evaluate the utility of the tissue Doppler echocardiographic technique in characterising diastolic and systolic functions in untreated native black African hypertensive subjects. MATERIALS AND METHODS: Forty consecutive, newly diagnosed, untreated hypertensives with adequate conventional echocardiographic (2-D, M-mode, transmitral and pulmonary Doppler flow velocities) and tissue Doppler echocardiographic images were recruited into the study. The control subjects were apparently normal individuals. Each arm of the study consisted of 21 male and 19 female subjects. RESULTS: The two groups were comparable by age (48.6 +/- 11.35 years in the hypertensives vs 48.1 +/- 11.33 years in the controls; p = 0.844) and gender distribution (M/F: 21/19 in both groups). Other baseline characteristics, except for blood pressure parameters, which were predictably higher in the hypertensive subjects, were comparable between the two groups. The hypertensive subjects had a lower systolic myocardial velocity (Sm) and early diastolic myocardial velocity (Em) in comparison with the controls (p = 0.033 and p = 0.018, respectively). The late diastolic myocardial velocity (Am) was comparable in the two groups (p = 0.430). CONCLUSIONS: Tissue Doppler echocardiography demonstrates diastolic dysfunction relatively early in native African hypertensives and may be useful for detecting subtle deterioration in systolic function.

Changes in left atrial dimension and function and left ventricular geometry in newly diagnosed untreated hypertensive subjects.

BACKGROUND: It is known that a spectrum of changes in structure, size and function of the different chambers of the heart occur in individuals with hypertension. The earliest changes and the sequence of these changes are still being studied. AIMS: The present study aimed to assess early changes in the left atrial size and function in hypertension, and its relationship with left ventricular geometry and other factors that may influence left atrial size. METHODS: One hundred consecutive subjects who were newly diagnosed with hypertension and 50 apparently normal individuals were recruited into the study. Standard M-mode, two-dimensional and Doppler echocardiography were performed. The endocardial border of the left atrium was traced to obtain the atrial area and left atrial volumes and emptying fractions were derived from measured areas. RESULTS: The hypertensive patients and the controls were comparable by age, sex and body mass index. Thirty-seven (37%) of the hypertensive subject had increased left ventricular mass versus eight subjects (16%) in the normal controls. The patients with hypertension had a higher linear left atrial dimension (3.5 +/- 0.48 cm versus 3.1 +/- 0.47 cm, P < 0.0001), longer pre-atrial contraction length (3.8 +/- 0.56 cm versus 3.6 +/- 0.45 cm; P = 0.02) and higher peak late mitral inflow velocity (0.64 +/- 0.19 m/s versus 0.56 +/- 0.15 m/s; P = 0.010). CONCLUSIONS: Changes in the geometry of the left ventricle occur early in hypertension and precede deterioration in left ventricular systolic function. The corresponding left atrial changes are marginal and are indicative of increased left atrial length and accentuated atrial systolic function.

Characterisation of left ventricular function by tissue Doppler imaging technique in newly diagnosed, untreated hypertensive subjects

BACKGROUND:Hypertension results in structural and functional changes in the heart. Early detection of abnormalities of cardiac structure and function is important in the assessment and treatment of hypertensive subjects. The aim of this study was to evaluate the utility of the tissue Doppler echocardiographic technique in characterising diastolic and systolic functions in untreated native black African hypertensive subjects.MATERIALS AND METHODS:Forty consecutive, newly diagnosed, untreated hypertensives with adequate conventional echocardiographic (2-D, M-mode, transmitral and pulmonary Doppler flow velocities) and tissue Doppler echocardiographic images were recruited into the study. The control subjects were apparently normal individuals. Each arm of the study consisted of 21 male and 19 female subjects.RESULTS:The two groups were comparable by age (48.6 +/- 11.35 years in the hypertensives vs 48.1 +/- 11.33 years in the controls; p = 0.844) and gender distribution (M/F: 21/19 in both groups). Other baseline characteristics, except for blood pressure parameters, which were predictably higher in the hypertensive subjects, were comparable between the two groups. The hypertensive subjects had a lower systolic myocardial velocity (Sm) and early diastolic myocardial velocity (Em) in comparison with the controls (p = 0.033 and p = 0.018, respectively). The late diastolic myocardial velocity (Am) was comparable in the two groups (p = 0.430). CONCLUSIONS:Tissue Doppler echocardiography demonstrates diastolic dysfunction relatively early in native African hypertensives and may be useful for detecting subtle deterioration in systolic function

Echocardiographic partition values and prevalence of left ventricular hypertrophy in hypertensive Nigerians.

BACKGROUND: Left ventricular hypertrophy (LVH) is a well known independent risk factor for cardiovascular events. It has been shown that combination of left ventricular mass (LVM) and relative wall thickness (RWT) can be used to identify different forms of left ventricular (LV) geometry. Prospective studies have shown that LV geometric patterns have prognostic implications, with the worst prognosis associated with concentric hypertrophy. The methods for the normalization or indexation of LVM have also recently been shown to confer some prognostic value especially in obese population. We sought to determine the prevalence of echocardiographic lLVH using eight different and published cut-off or threshold values in hypertensive subjects seen in a developing country's tertiary centre. METHODS: Echocardiography was performed in four hundred and eighty consecutive hypertensive subjects attending the cardiology clinic of the University college Hospital Ibadan, Nigeria over a two-year period. RESULTS: Complete data was obtained in 457 (95.2%) of the 480 subjects (48.6% women). The prevalence of LVH ranged between 30.9-56.0%. The highest prevalence was when LVM was indexed to the power of 2.7 with a partition value of 49.2 g/ht2.7 in men and 46.7 g/ht2.7 in women. The lowest prevalence was observed when LVM was indexed to body surface area (BSA) and a partition value of 125 g/m2 was used for both sexes. Abnormal LV geometry was present in 61.1%-74.0% of our subjects and commoner in women. CONCLUSION: The prevalence of LVH hypertensive patients is strongly dependent on the cut-off value used to define it. Large-scale prospective study will be needed to determine the prognostic implications of the different LV geometry in native Africans.