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ST segment depression elicited by dipyridamole infusion in asymptomatic hypertensive patients
E Picano1, A R Lucarini, F Lattanzi
1CNR Institute of Clinical Physiology and Clinica Medica I, University of Pisa, Italy.
Insights
Essential hypertension patients may show ischemic electrocardiogram changes with dipyridamole. This study found 36% of hypertensive patients had ST depression, unlike normotensive individuals, with no significant echocardiographic differences.
Area of Science:
- Cardiology
- Clinical Physiology
Background:
- Essential hypertension is linked to potential myocardial ischemia.
- Electrocardiographic (ECG) changes can indicate ischemia during pharmacologic stress.
Purpose of the Study:
- To investigate if dipyridamole infusion induces ischemic-like ECG changes in asymptomatic essential hypertension patients.
- To identify clinical and echocardiographic factors associated with this dipyridamole-induced response.
Main Methods:
- Dipyridamole-echocardiography testing was performed on 28 essential hypertension patients and 20 normotensive controls.
- A 12-lead ECG and two-dimensional echocardiography were monitored during a 10-minute dipyridamole infusion (0.84 mg/kg).
Main Results:
- 36% of hypertensive patients (10/28) exhibited ST segment depression (>0.1 mV), compared to 0% in normotensive controls (p<0.01).
- No significant differences were observed in baseline or peak dipyridamole fractional shortening between hypertensive responders and non-responders.
- Transmitral flow Doppler parameters (peak early to peak late velocity ratio) were similar between groups at baseline and peak dipyridamole.
Conclusions:
- Dipyridamole infusion can elicit ischemic-like ECG changes in a significant portion of asymptomatic essential hypertension patients.
- These ECG changes do not correlate with standard echocardiographic measures of systolic function or diastolic filling in this cohort.
Abstract:
In asymptomatic patients with essential hypertension, electrocardiographic changes suggestive of myocardial ischemia can be elicited by rapid pressure lowering or by pronounced coronary arteriolar dilation. The aim of this study was to assess whether dipyridamole infusion might induce ischemic-like electrocardiographic changes in asymptomatic essential hypertensive patients and to describe the clinical and echocardiographic correlates possibly associated with this response. We therefore studied a control group of 20 normotensive individuals and a group of 28 asymptomatic patients with mild-to-moderate essential hypertension. All underwent dipyridamole-echocardiography testing (12-lead electrocardiogram and two-dimensional echocardiographic monitoring with dipyridamole infusion, 0.84 mg/kg over 10'). No patient showed transient regional dyssynergy during dipyridamole infusion. None of the normotensive and 10 of 28 of the hypertensive participants had horizontal or downsloping ST segment depression more than 0.1 mV during dipyridamole (0% versus 36%, p less than 0.01). Hypertensive patients with ("responders") (n = 10) and without ("nonresponders") (n = 18) ST segment depression showed similar values of percent fractional shortening in baseline conditions (32 +/- 5 versus 33 +/- 6, p = NS) and at peak dipyridamole infusion (45 +/- 8 versus 43 +/- 5, p = NS). The peak early to peak late velocity ratio values (evaluated from transmitral flow tracings by Doppler technique) were also similar in baseline conditions (0.86 +/- 0.14 versus 0.94 +/- 0.30, p = NS) and at peak dipyridamole (0.72 +/- 0.15 versus 0.78 +/- 0.32, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)