Related Experiment Videos
Changes in coronary sinus pH during dipyridamole stress in patients with hypertrophic cardiomyopathy
P M Elliott1, G M Rosano, J S Gill
1Department of Cardiological Sciences, St George's Hospital Medical School, London.
Insights
Chest pain in hypertrophic cardiomyopathy (HCM) is linked to myocardial ischemia. Coronary sinus pH monitoring effectively detects this ischemia, aiding in assessing its impact on patient outcomes.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Angina pectoris and myocardial scarring in hypertrophic cardiomyopathy (HCM) suggest myocardial ischemia is involved in disease pathophysiology.
- Evaluating ischemia in HCM is challenging due to frequent baseline electrocardiographic abnormalities and poor correlation of thallium-201 perfusion defects with symptoms.
Purpose of the Study:
- To investigate the role of myocardial ischemia in patients with hypertrophic cardiomyopathy presenting with chest pain.
- To assess the utility of coronary sinus pH monitoring as a sensitive technique for detecting myocardial ischemia in HCM.
Main Methods:
- Studied 11 patients with HCM and chest pain, and 6 controls with atypical chest pain and normal coronary angiograms.
- Monitored coronary sinus pH continuously during dipyridamole infusion using a catheter-mounted pH electrode.
- Assessed baseline electrocardiography and thallium-201 scintigraphy in HCM patients.
Main Results:
- Maximal change in coronary sinus pH during dipyridamole stress was significantly greater in HCM patients compared to controls (P=0.02).
- In six HCM patients, chest pain development correlated with a decline in coronary sinus pH.
- No correlation found between left ventricular dimensions, maximal wall thickness, and maximum pH change.
Conclusions:
- The study provides evidence that chest pain in HCM patients is caused by myocardial ischemia.
- Coronary sinus pH monitoring is a valuable method for quantifying myocardial ischemia in HCM.
- Further research is needed to determine the role of myocardial ischemia in HCM pathophysiology and its prognostic implications.
Objectives:
The presence of angina pectoris and myocardial scarring in patients with hypertrophic cardiomyopathy (HCM) suggests that myocardial ischemia is a factor in the pathophysiology of the disease. The clinical evaluation of ischaemia is problematic in HCM as baseline electrocardiographic abnormalities are frequent and thallium-201 perfusion abnormalities correlate poorly with anginal symptoms. Coronary sinus pH measurement using a catheter mounted pH electrode is a validated sensitive technique for the detection of myocardial ischaemia.
Methods And Results:
11 patients with HCM and chest pain (eight men; mean (SD) (range) age 36 (11) (19-53) years) and six controls (two men; mean (SD) (range) age 49 (11) (31-62) years) with atypical pain and normal coronary angiograms were studied. Eight patients with HCM had baseline ST segment depression of > or = 1 mm and four had reversible perfusion defects during stress 201TI scintigraphy. A catheter mounted hydrogen ion sensitive electrode was introduced into the coronary sinus and pH monitored continuously during dipyridamole infusion (0.56 mg/kg over four min). The maximal change in coronary sinus pH during dipyridamole stress was greater in patients with HCM than in controls (0.082 (0.083) (0 to -0.275) v 0.005 (0.006) (0 to -0.012), P = 0.02). In six patients (four men; mean (SD) (range) age 29 (9) (19-40 years) the development of chest pain was associated with a gradual decline in coronary sinus pH (mean 0.123 (0.089)), peaking at 442 (106) s. There were no relations among left ventricular dimensions, maximal wall thickness, and maximum pH change. In patients with HCM there was a correlation between maximum pH change and maximum heart rate during dipyridamole infusion (r = 0.70, P = 0.02).
Conclusion:
This study provides further evidence that chest pain in patients with HCM is caused by myocardial ischaemia. The role of myocardial ischaemia in the pathophysiology of the disease remains to be determined but coronary sinus pH monitoring provides a method for quantifying and prospectively assessing its effects on clinical presentation and prognosis.