Dipyridamole echocardiography for diagnosis of coexistent coronary artery disease in hypertrophic cardiomyopathy

Prognostic role of stress echocardiography in hypertrophic cardiomyopathy: The International Stress Echo Registry

“…During dipyridamole (up to 0.84 mg/kg in 6 or 10 min) [7][8] or adenosine (0.14 mg/kg in 2 min), CFVR [13] sampled by pulsed Doppler on mid-distal left anterior descending artery was defined as the ratio between hyperemic peak and resting peak diastolic coronary flow velocities. A CFVR value ≤2.0 was considered abnormal [8].…”

“…Stress-induced electrocardiographic changes are relatively frequent in HCM patients, occurring in about 1 out of 3 individuals with angiographically normal coronary arteries [7,21]. Dilsizian et al [22] found ST-segment depression during exercise to be much more frequent in young HCM patients experiencing subsequent cardiac arrest than in asymptomatic ones.…”

“…Thallium myocardial perfusion scintigraphy demonstrated the presence of subendocardial ischemia or regional hypoperfusion [27][28], with a higher prevalence of left ventricular cavity dilatation. Physical or pharmacological stress-echo showed the presence of stress-induced new wall motion abnormality [6][7]29,36].…”

“…For instance, CVFR assessment was performed only in 116 out of the 146 vasodilator stresses. This is mainly due to the fact that dipyridamole SE was used for the first time in these patients in the early nineties, in the "firstgeneration" SE based only on wall motion analysis [7,21]. As data showing the key prognostic role of microvascular impairment in these patients became available over the next decade, and as the ultrasound imaging technology evolved and matured allowing the Doppler evaluation of left anterior descending artery in the last 15 years, the "second generation" vasodilator SE allowed to include the assessment of CFVR by different recruiting centers, some of which focused exclusively on CFVR, whereas others used the dual imaging (wall motion and CFVR) protocol.…”

“…Gradients ≥50 mm Hg, either at rest or after stress, represent the "conventional threshold for surgical or percutaneous intervention if symptoms cannot be controlled with medication" since they can possibly be responsible for symptoms [4][5]. Moreover, stress echocardiography (SE) may be used to enhance other signs potentially related to outcome such as transient regional wall motion abnormalities [6], stress-induced ST segment depression [7], and reduction in coronary flow velocity reserve (CFVR) (in the absence of regional wall motion abnormalities) due to microvascular impairment [8].…”