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.

Pulmonary hypertension in Nigerian adults with sickle cell anemia.

BACKGROUND: Sickle cell anemia (SCA) is the commonest hemoglobinopathy and is associated with high morbidity and mortality. Pulmonary hypertension (PH) is reported to play a significant role in this regard. There is very limited literature on PH in SCA in Nigeria. OBJECTIVES: The objectives of this study were to determine the prevalence of Doppler-derived PH in SCA, assess its influence on exercise capacity, and determine the correlates and predictors of measures of estimated pulmonary pressure. METHODS: A total of 92 SCA subjects had echocardiography and 6-minute self-paced walking exercise. PH was diagnosed by Doppler echocardiography on finding a tricuspid regurgitant velocity (TRV) of ≥2.5 m/s. The pulmonary flow profile was also assessed to estimate mean pulmonary arterial pressure (MPAP). RESULTS: Doppler-derived PH was detected in 23.9% of adults with SCA. The 6-minute walking distance (6MWD) was significantly lower in SCA adults with PH than in those without PH (380.33 ± 63.17 m vs 474.28 ± 76.74 m; p = 0.014). TRV and estimated MPAP had a significant inverse correlation with the 6MWD (r = -0.442; p < 0.001 and r = -0.571; p < 0.001, respectively). CONCLUSION: PH as derived by Doppler is common in Nigerian adults with SCA and has a significantly negative influence on exercise capacity. Screening for PH should be encouraged to optimize management and thus improve their quality of life and life expectancy.

Pulmonary Hypertension in Heart Failure Patients Presenting at OAUTHC, Ile-Ife, Nigeria.

BACKGROUND: Pulmonary hypertension (PH) is common in heart failure patients. Literature on PH in heart failure is sparse in Nigeria. This study was carried out to determine the prevalence of PH in heart failure patients and ascertain the relationship between left ventricular systolic and diastolic function and the degree of PH. METHODS: A total of 125 heart failure patients had echocardiography done. PH was diagnosed using tricuspid regurgitation jet and pulmonary ejection jet profile. RESULTS: PH was present in 70.4% of heart failure patients. Estimated mean pulmonary arterial pressure increased with increasing severity of systolic and diastolic dysfunction and had significantly negative correlation with ejection fraction, fractional shortening, and early mitral annular tissue diastolic velocity (E'), but positive correlation with left ventricular end-systolic volume, right ventricular dimension, transmitral E to A ratio, and E/E' ratio. CONCLUSION: PH is very common in heart failure and has significant relationship with left ventricular function.

Comparison between treadmill and bicycle ergometer exercise tests in mild-to-moderate hypertensive Nigerians.

BACKGROUND: Comparative cardiovascular responses to treadmill and bicycle ergometer (bike) exercise tests in hypertensive Nigerians are not known. This study compared cardiovascular responses to the two modes of exercise testing in hypertensives using maximal exercise protocols. METHODS: One hundred and ten male subjects with mild-to-moderate hypertension underwent maximal treadmill and bike test one after the other at a single visit in a simple random manner. Paired-sampled t-test was used to compare responses to both exercise tests while chi-squared test was used to compare categorical variables. RESULTS: The maximal heart rate (P<0.001), peak systolic blood pressure (P=0.02), rate pressure product (P<0.001), peak oxygen uptake (P<0.001), and exercise capacity (P<0.001) in metabolic equivalents were signifcantly higher on the treadmill than on the bike. CONCLUSION: Higher cardiovascular responses on treadmill in Nigerian male hypertensives in this study, similar to findings in non-hypertensives and non-Nigerians in earlier studies, suggest that treadmill may be of better diagnostic utility in our population.