Clinical significance of impaired heart rate recovery after treadmill exercise test in hypertensive patients

To evaluate the recovery time after a treadmill exercise ECG test in hypertensive patients and to study the role of beta-blockers on the recovery of the heart rate after exercise. Design: Prospective controlled study conducted between March 1998 and January 2002 with a follow-up after six months. Setting: A non-invasive cardiac laboratory, medical department, Farwania Hospital. We studied 250 patients and divided them into two groups. The first group included 170 untreated hypertensive patients [140 men and 30 women] and the control group included 80 normotensive patients [70 men and 10 women]. Echocardiography was done to assess left ventricular mass index and function. Exercise ECG test was done for all patients at baseline. Hypertensive patients were classified into two subgroups. The first subgroup included 70 patients with normal heart rate recovery [> 12 beat/minute] and the second subgroup included 100 patients with impaired heart rate recovery [< 12 beat/minute]. A beta-blocker was prescribed for 50 patients and other antihypertensive drugs was prescribed for another 50 patients for six months. The exercise ECG test was repeated again for all 100 patients. T h e re was a significant impaired diastolic function of the left ventricle in hypertensive patients with impaired heart rate recovery than those with normal heart rate recovery [p < 0.05]. However there was no significant difference regarding left ventricular mass index and systolic function. There was a significant decrease in resting and peak heart rate during exercise in patients with beta-blockers than those without beta- blockers. There was a significant decline in heart rate after exercise in patients with beta-blockers at a follow-up check up [p < 0.05]. The decline in heart rate during the first minute of recovery after exercise at follow-up was more increased as compared with the results of baseline exercise ECG test [p < 0.01]. Stepwise logistic analysis revealed a significant relation between the age of the patients and left ventricular diastolic dysfunction and impaired heart rate recovery after exercise in hypertensive patients [p < 0.05]. Impaired heart rate recovery after exercise in hypertensive patients is related to the age of the patients and the presence of left ventricle diastolic dysfunction and that beta-blockers affect heart rate in recovery, most likely due to an indirect effect by the reduction of chronotropism

Increased blood pressure variability in hypertensive patients with left ventricular hypertrophy

The aim of the study is to evaluate daytime blood pressure variability in hypertensive patients and to quantify its relation to left ventricular hypertrophy. Design: Observation study conducted between August 2001 and June 2002. Setting: Non-invasive cardiac laboratory, Medicine Department, Farwania Hospital. 100 patients were included in the study. All patients were referred from out-patient clinic in Farwania Hospital with blood pressure more than 140/90 mm Hg. Resting ECG and echocardiography were done to assess left ventricular hypertrophy [LVH]. Exercise ECG test was done to exclude patients with ischaemic heart disease. Ambulatory blood pressure was recorded with an auscultatory device to study blood pressure variability [BPV]. The patients were classified into two groups: Group I included 60 patients with left ventricular hypertrophy and Group II included 40 patients without left ventricular hypertrophy. There was a significant increase in age, serum cholesterol, LVMI and LV diastolic dysfunction [P<0.05], maximum systolic blood pressure and daytime systolic blood pressure load [P<0.05] in patients of Group I than those of Group II. There was a significant increase in, daytime systolic blood pressure [p<0.01], pulse pressure [P<0.05] and the mean blood pressure variability [P<0.05] in hypertensive patients with LVH than those without LVH. Correlation between daytime systolic BPvariability and LVH [p<0.05] was also significant. Stepwise logistic multivariate analysis revealed a significant relation with age [P<0.05], hypercholesterolemia [P<0.01], maximum SBP [P<0.05], daytime SBP load [P<0.01] and daytime SBP variability. There were significant increases in age, LVMI, maximum SBP, and daytime SBP load [P<0.05] in the fourth quintile of daytime SBP variability. There was a significant relation between blood pressure variability and left ventricular hypertrophy. This variability increased with age, hypercholesterolemia and increased BP load

Impaired heat rate recovery after exereise test in hypertensive patients

This work studied 70 untreated hypertensive patients [50 men and 20 women] and 30 normotensive subjects [20 men and 10 women]. Echocardiography was done to assess left ventricular mass index and function. Exercise ECG test was given for all patients at baseline. Hypertensive patients were classified into two subgroups: The first subgroup included 20 patients with normal heart rate recovery [>12 beats/minute] and the second subgroup included 50 patients with impaired heart rate recovery [<12 beats/minute]. Beta blocker was given to 25 patients and 25 patients received antihypertensive drugs not including beta blockers for six weeks and the exercise ECG test was repeated again for all 50 patients. It was concluded that the impaired heart rate recovery after exercise in hypertensive patients is related to the age of the patients and the presence of left ventricle diastolic dysfunction and that the beta blockers affect heart rate in recovery most likely due to an indirect effect by the reduction of chronotropism

Low - dose dobutamine stress echocardiography for assessment of myocarodial viability in patients with old myocardial infarction

Sixty patients with old myocardial infarction were included in this study. Echocardiography was done to assess the segmental wall motion abnormalities at rest. Dobutamine stress echocardiography test was done for all patients at dose of 5 mug/kg/min. for 5 minutes and 10 mug/kg/min. for 5 minutes. Thallium-201 myocardial scintigraphy was done for all patients. The same 20 segments division model used for dobutamine analysis was also applied to match echocardiographic finding. Thallium uptake in each myocardial segment was graded on a 5-point semiquantitative scale [from 0=absent to 2=normal]. A segment was considered viable if the assigned thallium score was 1 or higher [normal uptake or only mild moderate defect] in any of redistribution or reinjection images. From the results obtained, it was concluded that low-dose dobutamine echocardiography is a safe and useful tool in assessment of viable and non-viable myocardium

Clinic blood pressure measurements versus ambulatory blood pressure monitoring

To compare clinic [office] blood pressure [BP] measurement and ambulatory blood pressure monitoring [ABPM] in the clinical evaluation of hypertensive subjects. Hundred middle aged and pharmacologically untreated hypertensive subjects were studied [80 men and 20 women]. All subjects were referred fro m outpatient clinic in Farwania Hospital with BP greater than 140/90 mmHg. Resting ECG and echocardiography were done to assess left ventricular hypertrophy [LVH]. In order to exclude patients with ischemia an exercise ECG was done. Ambulatory blood pressure was recorded with an auscultatory device. There was a non -significant difference between the three clinical sessions in the measurement of the office systolic and diastolic BPreadings, [P= NS]. There was no significant intra-recording variation between the first and the second ABPM recordings when considering awake Aly M Hegazy, Bader AAbdel Kader Department of Medicine, Farwania Hospital, Kuwait and asleep maximum SBP, minimum systolic BP, maximum diastolic BP and minimum diastolic BP [P = NS]. Stepwise logistic analysis showed that ambulatory sleeptime and 24-hour systolic blood pressure had a significant relation to the presence of left ventricular hypertrophy [P < 0.05]. There was a good agreement between clinic BP readings and ambulatory daytime systolic and diastolic BP recordings as there was a good distribution of values between upper and lower limits of a g reement [mean +/- 2SD]. There was a significant c o r relation between office systolic BPreadings and awake systolic ABPM recordings [r = 0.954, P < 0.01]. Measured by non-physicians, clinic BP is as reliable as ambulatory BP monitoring in the clinical evaluation of untreated hypertensive patients. Asleep ABP, 24-hour ambulatory BP and daytime systolic BP variability were also shown to be good indicators of left ventricular hypertrophy

Increased blood pressure variability in hypertensive patients with left ventricular hypertrophy

The aim of this study was to evaluate the daytime blood pressure variability in hypertensive patients and to quantify the relation to left ventricular hypertrophy. Sixty patients were included in the study. Resting ECG and echocardiography were done to assess left ventricular hypertrophy [LVH]. Exercise ECG test was done to exclude patients with ischemic heart disease. Ambulatory blood pressure was recorded with an auscultatory device to study the blood pressure variability [BPV]. The patients were classified into two groups: Group I included 30 patients with left ventricular hypertrophy and group II included 30 patients without left ventricular hypertrophy. It was concluded that there was a significant relation between blood pressure variability and left ventricular hypertrophy and this variability increased with age, hypercholesterolemia and increased BP load

Clinic blood pressure measurements versus ambulatory blood pressure monitoring

The objective of this study was to compare clinic [office] blood pressure [BP] measurement and ambulatory blood pressure monitoring [ABPM] in the clinical evaluation of hypertensive subjects. Fifty middle aged and pharmacologically untreated hypertensive subjects were studied [40 men and 10 women]. All subjects were referred with BP greater than 140/90 mmHg. Resting ECG and echocardiography were done to assess left ventricular hypertrophy [LVH]. In order to exclude patients with ischemia, exercise ECG test was done. Ambulatory blood pressure was recorded with an auscultatory device. It was concluded that measured clinic BP is as reliable as ambulatory BP monitoring in the clinical evaluation of untreated hypertensive patients. Asleep ABP and 24-hour ambulatory BP appeared to be good indicators of left ventricular hypertrophy

Heart rate variability in hypertensive patients with left ventricular diastolic dysfunction

This study aimed to evaluate the role of autonomic nervous system in determining the appearance of diastolic ventricular dysfunction in patients with previously unrecognized and untreated essential hypertension. Sixty middle aged and pharmacologically untreated hypertensive subjects [45 men and 15 women] and 30 normotensive subjects [24 men and 6 women] as a control group [group I] were studied. All patients were referred from outpatient clinic with blood pressure morethan 140/90 mmHg as detected by ambulatory blood pressure monitoring with an auscultatory device. Echocardiography was done to assess left ventricular diastolic function. Exercise ECG test was done to exclude patients with ischaemic heart disease. Holter ECG monitor was done for all subjects to assess heart rate variability. Hypertensive patients were classified into two groups: Group II included 30 patients with diastolic dysfunction and group III included 30 patients with normal ventricular systolic function. In regard of age, gender, left ventricular mass index and left ventricular systolic function, there was no significant difference between all the groups of study; but the hypertensive patients of group II had a significant decreased E/A ratio, a significant decreased r-MSSD and p-NN50 and a significant increased daytime and nighttime heart rate than subjects and patients of groups I and II. There was a significant correlation between vagal dependent parameter [r-MSSD] and E/A ratio. Stepwise logistic analysis revealed that there was no significant relation between age, gender and ambulatory systolic and diastolic blood pressure and the presence of left ventricular diastolic dysfunction in hypertensive patients. It was concluded that left ventricular diastolic dysfunction in hypertensive patients without left ventricle hypertrophy is related to reduced parasympathetic activity and this supports the use of non-pharmacologic treatments that increase vagal tone

Left ventricular systolic and diastolic functions in diabetic patients without clinical evidence of cardiovascular diseases

Diabetic microangiopathy and myocardial cellular alterations occur commonly in diabetics and present themselves in variety of symptoms which may be involved in the entity of diabetic cardiomyopathy. Left ventricular function was studied using M-mode and Doppler echocardiography in 40 adult onset diabetic patients without clinical evidence of cardiac diseases and 15 normal controls, all of them have normal resting ECG and stress test. The data obtained from this study have shown impaired left ventricular diastolic function as evidence by the reversed E/A ratio [E, early rapid diastolic inflow, A = late diastolic inflow due to atrial contraction] in diabetics compared to controls although the end diastolic dimension was not significantly different in both groups and this may indicate that the presence of diabetic cardiomyopathy may be reflected early by impaired left ventricular diastolic function which may later on, present clinically with the overt left ventricular failure

Extent and functional capacity of coronary collateral circulation in the hypertensive patients with atherosclerotic coronary artery disease

This study was an evaluation of coronary collateral circulation in relation to the presence of systemic hypertension and left ventricular hypertrophy. One hundred patients with significant coronary artery disease [>75%] were enrolled in the study. 35 hypertensive patients with left ventricular hypertrophy [LVH] were considered as group I, 35 hypertensive patients without LVH as group II and 30 normotensive patients as group III. Coronary angiography was done for all patients. Class 0: No collateral, class I: Partial filling and class II: Complete filling of collaterals were used as angiographically classified coronary collaterals. Echocardiography and graded exercise ECG test were done for all patients. From the results obtained, it was concluded that patients with systemic hypertension and coronary artery disease have an increase in coronary collateral circulation corresponding to the left ventricular hypertrophy and that functional capacity of the coronary collateral circulation is not augmented by left ventricular hypertrophy

Impaired flow-dependent coronary vasomotor reactivity of infarct-related artery after coronary angioplasty

The aim of this work is to study the vasomotor reactivity of infarct- related artery after coronary angioplasty in patients with acute myocardial infarction [AMI]. 20 patients with anterior myocardial infarction were included in the study. Thrombolytic therapy was administered to all patients. The patients underwent coronary angiography there were two or five weeks after thrombolytic therapy. According to coronary angiography, there were two groups of patients, group I: Included 10 patients who had residual stenosis >50% after thrombolysis and underwent PTCA for infarct-related artery and group II: Included 10 patients who had residual stenosis <50% after thrombolysis and were not candidates for PTCA. Intracoronary injection of papaverine [PAP] through diagnostic and guiding catheter followed by nitroglycerine [NTG] infusion after 5 minutes. Automatic vessel-segment diameter was detected in end diastolic frames. It is concluded that there was a significant decreased vasomotor reactivity to injection of papaverine after PTCA in patients who received thrombolytic therapy and these changes were not significantly correlated to residual stenosis after angioplasty

Acute Q-wave versus non Q-wave myocardial infarction: clinical and regional wall motion abnormality studies

Clinical spectrum and echocardiography studies were performed on 30 patients divided into two groups. Group I [QMI group] included 16 patients and group II [NQMI group] included 14 patients. Early echocardiography was done 24 hours after infarction and another one was done after 2 weeks. There was no difference between both groups as regards clinical data. There was a highly significant increased duration of symptoms before infarction [P <0.01] and a significantly increased number of ischemic episodes after infarction [P <0.05] in the NQMI group than QMI group. There was a highly significant increased CPK-MB enzyme in the QMI group than NQMI group [P <0.01]. There was no statistically significant difference between both groups as regards the segmental wall motion abnormalities early after myocardial infarction, but after 2 weeks there was a highly significant decreased wall motion score in the NQMI than the QMI groups [P <0.01]. There was a significant decrease in wall motion score [WMS] between early and late echocardiography [P <0.05] in the NQMI group, but there was a nonsignificant difference between the two echocardiograms WMS in the QMI group. So, the present study suggested that NQMI is more unstable than the QMI in the clinical course. Improvement in regional wall motion suggested increased risk of future ischemic events in the NQMI group. Serial echocardiographic imaging may be used to identify patients at risk for infarct extension in both QMI and NQMI patients

Study of load-independent index of left ventricular myocardial contractility in infants with isolated ventricular septal defect and congestive heart failure

Twenty-nine infants with isolated VSD [15 symptomatic and 14 asymptomatic] and with age ranged from 5 to 14 months were compared with 15 control infants, to determine if symptoms of congestive heart failure were due to depressed contractility or defect size or both. We found that the symptomatic infants had a significant increased heart rate and respiratory rate [P < 0.01] and a significant lower systolic blood pressure [P < 0.05] than the other groups. The symptomatic patients had non significant increased ESD, EDD and End-systolic stress [ESS] than other groups of the study but there was no significant difference between the three groups as regards fractional shortening [FS] and velocity of circumferential fiber shortening [VCFc]. We found that the left ventricular contractility in the symptomatic patients was not depressed as the predicted VCFc was lower than the measured VCFc, at any given ESS. The ESS/VCFc curve slope of the symptomatic patients [-0.005] was less than asymptomatic patients [-0.009] and the control infants [-0.012] and shifted to the right, due to increased LV preload and wall stress as the symptomatic patients had a significant bigger VSD and a significant increased pulmonary/ systemic flow ratio [Qp/Qs] than asymptomatic patients [P < 0.01]. It is concluded that the left ventricular contractility in patients with VSD and CHF was not depressed and their symptoms may be related to increased pulmonary flow due to increased left- to -right shunt through a big VSD

Study of aortic function in the normotensive pregnant woman

Arterial rupture and dissection have been observed in both normal and complicated pregnancies. To understand how arterial mechanical properties might change during pregnancy we measured aortic root diameter by M-mode echocardiography and obtained simultaneous cuff blood pressure at rest and during hand grip isometric exercise. Measurements were obtained in 25 pregnant women [13 primiparous and 12 multiparous women] at the late period of normal gestation, and again 3 months postpartum. There was significant increase of cardiac index [CI] and significant increase of AO/LA ratio at late gestation than postpartum [P< 0.05] in both groups. There was a significant increase in aortic root area index and significant increase of aortic compliance [P<0.05] in multiparous than primiparous women at late gestation and there were significant increased aortic root area index and increase of aortic compliance [P< 0.05] in multiparous at late gestation than postpartum in both groups. The aorta is larger and more compliant during normal human pregnancy especially in multiparous women. Increased aortic compliance may enhance left ventricular performance in normal pregnancy. So, multiparous women have more structural alteration of aorta leading to dissection or rupture during pregnancy

Treadmill test verus Holter monitoring in detection of silent myocardial ischaemia in patients with chronic stable angina

The study was conducted on 34 patients with chronic stable angina [31 males and 3 females] with the age ranging from 29 to 67 years with a mean 49.7 years. Treadmill exercise ECG test showed that 27 patients [79 percent] had a positive result and 7 patients [21 percent] had a negative result. Ten patients [29 percent] had silent ST-segment depression. During Holter monitoring, a total of 48960 minutes were analyzed: 1841 minutes of ischaemic activity were recorded, 1564 minutes [85 percent] were silent. The total number of ischaemic episodes recorded, 147 of which 112 [76 percent] were silent. The total number of patients who developed silent ischaemic on Holter monitoring was 18 patients [54 percent]. Seventeen patients [94 percent] out of those 18 patients had a positive stress test result and one patient [6 percent] had a negative result [P<0.01]. Silent ischaemic episodes are more frequent among patients who developed earlier ST-segment depression on exercise and at lower heart rate and if ischaemica persisted after exercise. The two methods of investigation seem to complement each other in clinical practice to identify subgroup of patients with stable angina at a higher risk of cardiac events