Prevalence and determinants of late potentials in patients with unstable angina

To study the factors determining the positivety of late potentials and its prevalence in unstable angina, fifty unstable angina patients together with a sex and age matched twenty stable angina patients serving as control were included in this study. All were subjected to careful history taking and clinical examination, laboratory blood analysis; twelve leads resting surface ECG; echo-Doppler study; 24-hours Holterniortitoring and signal averaged ECG [SAECG] namely filtered QRS complex duration, root of the mean square of signal amplitude in the last 40 msec of the filtered QRS and the duration of terminal filtered low signal amplitude [LAS] with frequency amplitude<40 uv. Echo-Doppler; Holter monitoring and SAECG were repeated two weeks later for the unstable angina patients. Exercise treadmill was done to confirm the diagnosis of stable angina patients. In the present study the incidence of positive LPs was 24% on admission and was significantly reduced to 14% after 2 weeks of medical therapy in unstable angina patients. However, non of the stable angina patients had positive LPs. All the parameters of SAECG were significantly higher in the unstable angina patients. Sex and age had no effect on the incidence of LPs, inferior ischemia had significantly higher positive LPs than anterior ischemia [55% vs 33%/. Holter-reported ischaemic episodes and echo-reported regional wall motion abnormalities were significantly positively correlated with positive LPs. The presence of left ventricular systolic and diastolic dysfunction significantly increase the incidence of positive LPs and their improvement significantly reduce the incidence of positive LPs Positive LPs was recorded in 24% of patients with unstable angina Left ventricular systolic and diastolic dysfunction and the frequency of ischaemic episodes showed significant positive correlation with the incidence of positive LPs Medical therapy significantly reduced the incidence of positive LPs

Effect of hypertension on pulmonary function

Thirty hypertensives and ten normal control subjects were included in the study, all had a normal left ventricular systolic function, no clinical or radiological pulmonary disease, fifteen hypertensives had diastolic dysfunction. Echo-Doppler and ventilatory pulmonary function studies were done for all. There was a significant inverse relation between E/A ratio and both the age and level of BP in hypertensive, but a significant direct relation with EF. Hypertensives with normal diastolic function showed a significant decrease in F.E.V[1] and M.V.V. and a significant increase in F.E.V[1]/F.V.C. but still within the normal range. Hypertensives with diastolic dysfunction had a combined obstructive-restrictive ventilatory dysfunction as represented by a significant decrease in V. C, F.V. C, F.E.F and M.V.V. less than normal range. However the effect of hypertension on small airways was insignificant B.P = Blood Pressure E.F = Ejection Fraction F.E.V[1] = Forced Expiratory Volume at the first second M.V.V = Maximal Volantary Ventilation F.V.C. = Forced Vital Capacity. V.C. = Vital Capacity. P.E.F. = Peak Expiratory Flow