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[Blood pressure variability and transient myocardial ischemia in patients with essential hypertension]
E C Lanitz1, B D Gonska, J Schrader
1Abt. für Kardiologie und Pulmonologie, Medizinische Universitätsklinik Göttingen.
Insights
Transient myocardial ischemia can occur in hypertensive heart disease even without coronary artery disease. While heart rate often increases before ischemia, a strong link between blood pressure and ST-segment depression was not established.
Area of Science:
- Cardiology
- Hypertension Research
- Ischemic Heart Disease
Context:
- Essential hypertension is a significant risk factor for cardiovascular events.
- Assessing myocardial ischemia in hypertensive patients is crucial for risk stratification.
- Coronary artery disease (CAD) is a common cause of myocardial ischemia.
Purpose:
- To investigate the relationship between myocardial ischemia, heart rate, and blood pressure variations in patients with essential hypertension.
- To determine if transient myocardial ischemia occurs independently of significant coronary artery disease.
Summary:
- ST-segment depression (ST-D) during ambulatory monitoring was analyzed in 78 hypertensive patients, with and without angiographically proven CAD.
- ST-D was observed in both groups, with different characteristics in duration and magnitude.
- Most ST-D episodes were preceded by heart rate increases, but significant blood pressure elevation accompanied ischemia in a smaller proportion of cases.
Impact:
- Transient myocardial ischemia can be detected in hypertensive patients even without obstructive CAD.
- Findings suggest that hypertensive heart disease itself may contribute to ischemic episodes.
- The study highlights the complexity of ischemic events in hypertension, with heart rate being a more consistent correlate than blood pressure.
Abstract:
To determine whether myocardial ischemia is accompanied by variation in heart rate and/or blood pressure, ST-segment analysis on Holter-ECG and ambulatory blood pressure monitoring was performed in 78 patients (64 males/14 females) with essential hypertension. Thirteen out of 55 patients (24%) with angiographically proven coronary artery disease (CAD) showed ST-segment depression (ST-D; group A pos). We observed 41 ST-D (1-11 ST-D; median: 2) lasting from 1 min to 70 min 15 s (median: 4 min 42 s) and an average depression of 185 +/- 48 mV. In comparison, in 6 of 23 patients (26%) with a normal angiogram 24 ST-D (1-10; median: 3; group B pos), which showed longer duration (1 min to 109 min 20 s; median: 11 min 10 s) and less depression (137 +/- 47 mV) have been found. 73.3% of all ST-D in group A pos and all in group B pos were preceded by an average increase in heart rate of 13 bpm. Exclusively, 12 episodes of ischemia (29.3%) in patients with CAD and 8 (33.3%) in patients without CAD were accompanied by an increase in blood pressure, which was more distinct in group A pos. Transient myocardial ischemia can be shown in hypertensive heart disease unrelated to CAD. A clear correlation between an increase in blood pressure and ST-D could not be proven.