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Combined protocols for myocardial perfusion imaging in patients with hypertension
G Panoutsopoulos1, E Savari, I Ilias
1Department of Nuclear Medicine, Sotiria Hospital, Athens, Greece. ilias@compulink.gr
Insights
Combined dipyridamole and exercise protocols safely enhance myocardial scintigraphy in hypertensive patients. Treadmill exercise is preferred, with handgrip exercise suitable for those with physical limitations.
Area of Science:
- Cardiology
- Nuclear Medicine
- Diagnostic Imaging
Background:
- Hypertension poses challenges for exercise stress testing, often causing excessive blood pressure elevation.
- This can lead to test interruptions or inaccurate results for coronary artery disease.
- Myocardial scintigraphy is a key diagnostic tool for assessing heart function.
Purpose of the Study:
- To evaluate hemodynamic changes and safety of combined dipyridamole and exercise protocols.
- To compare dipyridamole with handgrip exercise versus treadmill exercise in hypertensive patients.
- To assess the efficacy of these combined protocols for myocardial scintigraphy.
Main Methods:
- Single photon emission computed tomography myocardial scintigraphy was performed in 240 hypertensive patients.
- Protocols included dipyridamole alone, dipyridamole plus isometric handgrip exercise, and dipyridamole plus symptom-limited treadmill exercise (modified Bruce protocol).
- Hemodynamic parameters (blood pressure, heart rate) and cardiac complications were monitored.
Main Results:
- Combined dipyridamole and exercise protocols did not result in excessive blood pressure elevation.
- Systolic blood pressure averaged 192/106 mmHg (handgrip) and 180/104 mmHg (treadmill).
- No major cardiac complications occurred; exercise groups reported fewer side effects than dipyridamole alone.
Conclusions:
- Combined dipyridamole and exercise protocols are safe for myocardial scintigraphy in hypertensive patients.
- These protocols effectively increase heart rate without significant blood pressure spikes.
- Dipyridamole with treadmill exercise is recommended; handgrip exercise is an alternative for physically impaired patients.
Objective:
Patients diagnosed previously with hypertension submitted to exercise testing for myocardial scintigraphy often respond with excessive elevation of the blood pressure, even when baseline blood pressure is normal, resulting in interruption of the test or false positive results for coronary artery disease. The aim of this study was to evaluate the haemodynamic changes and the safety of the combined examination protocols of dipyridamole plus handgrip exercise and of dipyridamole plus symptom-limited exercise testing on a treadmill in patients with hypertension.
Methods And Results:
We performed scintigraphic myocardial single photon emission computed tomography in 240 patients with hypertension as follows: in 27 patients who were administered dipyridamole alone, in 126 patients who were administered dipyridamole and were also submitted to isometric handgrip exercise and in 87 patients who were administered dipyridamole and were also submitted to treadmill, symptom-limited exercise (modified Bruce protocol). Mean systolic blood pressure, mean diastolic blood pressure and heart rate did not rise excessively in patients submitted to exercise testing (192 +/- 18 mm Hg, 106 +/- 14 mm Hg and 111 +/- 21 bpm for the dipyridamole plus handgrip group and 180 +/- 28 mm Hg, 104 +/- 10 mm Hg and 149 +/- 19 bpm for the dipyridamole plus treadmill group, respectively), with two patients from each exercise group presenting a maximum systolic blood pressure higher than 220 mm Hg and no subsequent major cardiac complications (such as death, myocardial infarction, unstable angina or life-threatening arrhythmia). Moreover, patients in these exercise groups experienced fewer non-cardiac side effects than with dipyridamole alone, while attaining a good level of exercise stress.
Conclusions:
Both combined dipyridamole and exercise protocols for scintigraphic myocardial single photon emission computed tomography in patients with hypertension are safe and increase heart rate without an excessive elevation in blood pressure. Consequently, they can be recommended for clinical use. Dipyridamole combined with treadmill, symptom-limited exercise would be the first choice, with dipyridamole and isometric handgrip exercise reserved for patients with physical handicaps.