Effects of Beta Blockade on the Relation Between Heart Rate and Ventricular Diastolic Perfusion Time During Exercise in Systemic Hypertension Giuseppe Ferro, MD, Franc0 Guarnaccia,
Carlo Duilio, MD, Letizia Spinelli, and Mario Condorelli, MD
MD,
Marco Spadafora,
MD,
MD,
t is well known that cardiovascular response to exer- emia were included in this study. After informed concise involves sympathetic stimulation of the heart sent to participate in the study, they were enrolled and peripheral vesselsand that ,f3blockade interferes according to thefollowing criteria: normal electrocarwith adrenergic response during exercise. When a de- diogram and echocardiogram, normal thallium-201 and technetium-99m scintigraphies at rest and during crease in heart,rate is prevented by atria1 pacing, regional myocardial function and blood flow in ischemic areas exercise. All patients underwent upright bicycle exertend to be more depressed after @blockade, suggesting cise before and 3 weeks after receiving p blockade that p blockade could unmask an ~2 adrenergic vasocon- (metoprolol 200 mglday). All stress tests were performed in the morning (9 to 12 A.M.). The test began striction, worsening regional blood flow and function.’ An alternative hypothesis might be that p blockade mod- with an initial work load of SO Wand was increased ifies the relation between diastolic time and heart rate. In 20 W every 2 minutes. At rest and during the exercise fact, there is also some evidence that p blockade impairs test, the electrocardiographic leads were monitored by the postexercise diastolic time in patients with coronary a computer-assisted system (Case Marquette). Furartery disease.2 However, this effect is not clearly ex- thermore, an electrocardiographic lead and a pulse plained, since ischemia alone could interfere with diastole tracing, obtained by ear photoplethismography duration.334 Moreover, the effect of p blockade on dia- (Rentsch’s apparatus), were recorded by an Irex II stolic time during exercise is still unknown. This study system at a paper speed of 100 mm/s. Two indepeninvestigates the effects of ,L?blockade on diastolic time dent observersunaware ofpatient characteristics read during exercise in hypertensive patients without stress- the recordings. The results of these readings were induced myocardial ischemia. averaged and the mean value was used in statistical Eight hypertensive patients (6 men and 2 women, analysis of our data. Simultaneous measurements of arterial blood pressure, measured with a cuff sphygmean age 47 f 5 years) without stress-induced isch-
I
From the Department of Medicine, Division of Cardiology, Second Medical School, University of Naples, Italy. Dr. Ferro’s address is: Via Pezzullo, 30, 80027 Frattamaggiore, Naples, Italy. Manuscript received April 1,199l; revised manuscript received and accepted May 28, 1991.
TABLE I Heart Beta Blockade
Rate, Systolic
and Diastolic
Heart rate (beats/mid B A P Systolic BP (mm Hg) B A P Diastolic BP (mm Hg) B A P Diastolic time (ms) B A P
Blood Pressure,
Diastolic
momanometer, and pulse tracings were also obtained at rest and at each stage of exercise. The following parameters were analyzed: heart rate, diastolic time, and systolic and diastolic blood pressures. The values of diastolic time represent the mean of 2.5 consecutive Time at Rest and
During
Exercise
Before (B) and After (A)
Rest (n = 8)
5ow (n = 8)
7ow (n = 8)
9ow (n = 5)
89 f 8 76 f 17 -co.05
111 2 10 95 2 12
Carlo Duilio, MD, Letizia Spinelli, and Mario Condorelli, MD
MD,
Marco Spadafora,
MD,
MD,
t is well known that cardiovascular response to exer- emia were included in this study. After informed concise involves sympathetic stimulation of the heart sent to participate in the study, they were enrolled and peripheral vesselsand that ,f3blockade interferes according to thefollowing criteria: normal electrocarwith adrenergic response during exercise. When a de- diogram and echocardiogram, normal thallium-201 and technetium-99m scintigraphies at rest and during crease in heart,rate is prevented by atria1 pacing, regional myocardial function and blood flow in ischemic areas exercise. All patients underwent upright bicycle exertend to be more depressed after @blockade, suggesting cise before and 3 weeks after receiving p blockade that p blockade could unmask an ~2 adrenergic vasocon- (metoprolol 200 mglday). All stress tests were performed in the morning (9 to 12 A.M.). The test began striction, worsening regional blood flow and function.’ An alternative hypothesis might be that p blockade mod- with an initial work load of SO Wand was increased ifies the relation between diastolic time and heart rate. In 20 W every 2 minutes. At rest and during the exercise fact, there is also some evidence that p blockade impairs test, the electrocardiographic leads were monitored by the postexercise diastolic time in patients with coronary a computer-assisted system (Case Marquette). Furartery disease.2 However, this effect is not clearly ex- thermore, an electrocardiographic lead and a pulse plained, since ischemia alone could interfere with diastole tracing, obtained by ear photoplethismography duration.334 Moreover, the effect of p blockade on dia- (Rentsch’s apparatus), were recorded by an Irex II stolic time during exercise is still unknown. This study system at a paper speed of 100 mm/s. Two indepeninvestigates the effects of ,L?blockade on diastolic time dent observersunaware ofpatient characteristics read during exercise in hypertensive patients without stress- the recordings. The results of these readings were induced myocardial ischemia. averaged and the mean value was used in statistical Eight hypertensive patients (6 men and 2 women, analysis of our data. Simultaneous measurements of arterial blood pressure, measured with a cuff sphygmean age 47 f 5 years) without stress-induced isch-
I
From the Department of Medicine, Division of Cardiology, Second Medical School, University of Naples, Italy. Dr. Ferro’s address is: Via Pezzullo, 30, 80027 Frattamaggiore, Naples, Italy. Manuscript received April 1,199l; revised manuscript received and accepted May 28, 1991.
TABLE I Heart Beta Blockade
Rate, Systolic
and Diastolic
Heart rate (beats/mid B A P Systolic BP (mm Hg) B A P Diastolic BP (mm Hg) B A P Diastolic time (ms) B A P
Blood Pressure,
Diastolic
momanometer, and pulse tracings were also obtained at rest and at each stage of exercise. The following parameters were analyzed: heart rate, diastolic time, and systolic and diastolic blood pressures. The values of diastolic time represent the mean of 2.5 consecutive Time at Rest and
During
Exercise
Before (B) and After (A)
Rest (n = 8)
5ow (n = 8)
7ow (n = 8)
9ow (n = 5)
89 f 8 76 f 17 -co.05
111 2 10 95 2 12
