Detection of myocardial ischemia based on QTc dispersion in the dipyridamole stress test

Abstract Background Coronary microvascular dysfunction (CMD) is a potential cause of myocardial ischemia and may affect myocardial function at rest and during stress. CMD can be identified, in patients with non-obstructive coronary artery disease (CAD), by a reduced transthoracic Doppler-derived coronary flow reserve (CFR), which is an index of coronary arterial reactivity, and can be impaired in both obstructive CAD and CMD. The aim of this study was to investigate the dipyridamole-induced changes of global longitudinal strain (GLS) in patients with CMD. Methods 43 patients (29M, 14F; mean age 68±7 years) without obstructive CAD, assessed by invasive coronary angiogram, underwent dipyridamole stress echocardiography. Coronary flow was assessed in the left anterior descending coronary artery (LAD) and was identified as the colour signal directed from the base to the apex of the left ventricle, containing the characteristic biphasic pulsed-Doppler flow signals. CFR were determined as the ratio of hyperaemic to baseline diastolic coronary flow velocity. CMD was defined as CFR <2. GLS was measured using automated function imaging, through the positioning of three endocardial markers (two markers at the mitral annulus and one at the apex) in each apical view. Subsequently, the obtained segmental values of GLS were visualized as a bull's-eye map in a quick and feasible manner. We had optimal left ventricular endocardial tracking in the overall population. In each patient, we used a frame rate of 70 frames/sec for adequate 2D strain analysis. We analyzed GLS at each step of stress test and compared peak-dose values with baseline. Results Thirteen patients (30%) among the overall population showed CMD. There were no significant differences in baseline characteristics between patients with or without CMD. GLS, at baseline, was significantly lower in patients with CMD (−16.9±3.78 vs. −17.8±3.77 – p<0.01). We observed a different response to dipyridamole stress echocardiography, between the two groups: GLS significantly increased up to peak dose in patients without CMD (from −17.8±3.77 to −19.3±4.09 – p<0.01), whereas on the other hand, a significant decrease from rest to peak dose was observed in patients with CMD (from −16.9±3.78 to −15.5±4.18 – p<0.01). There was a significant inverse correlation between CFR and delta GLS measured at rest and after dipyridamole peak dose (r=−0.82 – p<0.01). Conclusions GLS analysis, particularly performed by comparing dipyridamole peak-dose with baseline values, shows that in patients with CMD there is a different response of left ventricular myocardiim to stress test. It could be assumed that the inverse correlation between CFR and delta GLS reflects a progressive subclinical worsening of left ventricular myocardial function in these patients. Larger studies could confirm our data. Funding Acknowledgement Type of funding source: None

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Abstract 2941: Combined Assessment of Coronary Artery Stenosis and Myocardial Ischemia by Rest-Dipyridamole Stress Multidetector Computed Tomography

Circulation ◽

10.1161/circ.116.suppl_16.ii_656-b ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Patricia M Carrascosa ◽

Carlos Capuñay ◽

Jorge Carrascosa ◽

Alejandro Deviggiano ◽

Alejandro Goldsmit ◽

...

Keyword(s):

Computed Tomography ◽

Coronary Artery Disease ◽

Coronary Artery ◽

Myocardial Ischemia ◽

Contrast Enhancement ◽

Coronary Artery Stenosis ◽

Artery Stenosis ◽

Artery Disease ◽

Mdct Coronary Angiography ◽

Dipyridamole Stress

Introduction: MDCT coronary angiography has been evolving as a noninvasive method for the assessment of coronary artery disease (CAD). More recently, It has been demonstrated that MDCT identifies reduced contrast enhancement in ischemic and/or scarred myocardial segments. Objective: to determine the ability of rest-stress multidetector computed tomography (RS-MDCT) to detect myocardial ischemia and to assess the relationship between MDCT myocardial perfusion abnormalities and coronary artery stenosis. Methods: Forty seven patients underwent stress/rest 99mTc sestamibi SPECT and RS-MDCT, using a 16-row detector scanner (Philips Brilliance-16). Myocardial segments were classified by SPECT as normal, ischemic or scarred. SPECT results were then compared with MDCT regional myocardial contrast enhancement. The results of MDCT coronary angiography were also analyzed in 20 patients who underwent invasive catheterization. Results: The presence of a reduction in contrast enhancement at rest by MDCT identified scar by SPECT with 96% sensitivity and 98% specificity. A stress-induced reduction in contrast enhancement by MDCT identified ischemia by SPECT with 77% sensitivity and 99% specificity. The segment-based sensitivity and specificity for the detection of significant stenosis by MDCT were 92% and 98%, respectively. Conclusion: Our results showed that a rest-dipyridamole stress MDCT protocol can identify the presence of myocardial ischemia as well as the severity of coronary artery stenosis in patients with suspected coronary artery disease.

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Abstract 12727: Microvascular Coronary Dysfunction Affects Global Longitudinal Strain After Dipyridamole Stress Echocardiography

Circulation ◽

10.1161/circ.142.suppl_3.12727 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Ercole Tagliamonte ◽

Caterina Montuori ◽

Roberta Astarita ◽

Lucia Riegler ◽

Alberto Forni ◽

...

Keyword(s):

Stress Echocardiography ◽

Myocardial Function ◽

Stress Test ◽

Global Longitudinal Strain ◽

Inverse Correlation ◽

Left Ventricular ◽

Peak Dose ◽

Different Response ◽

Dipyridamole Stress Echocardiography ◽

Dipyridamole Stress

Introduction: Coronary microvascular dysfunction (CMD) is a potential cause of myocardial ischemia and may affect myocardial function. CMD can be identified, in patients with non-obstructive coronary artery disease (CAD), by a reduced transthoracic Doppler-derived coronary flow reserve (CFR), which is an index of coronary arterial reactivity. Hypothesis: The aim of this study was to investigate the dipyridamole-induced changes of global longitudinal strain (GLS) in patients with CMD. Methods: fiftythree patients (35M, 18F; mean age 67±8 years) without obstructive CAD, assessed by invasive coronary angiogram, underwent dipyridamole stress echocardiography. CFR were determined as the ratio of hyperaemic to baseline diastolic coronary flow velocity. CMD was defined as CFR < 2. GLS was visualized as a bull’s-eye map in a quick and feasible manner. In each patient, we used a frame rate of 70 frames/sec for adequate 2D strain analysis. We analyzed GLS at each step of stress test and compared peak-dose values with baseline. Results: Sixteen patients (30%) among the overall population showed CMD. There were no significant differences in baseline characteristics between patients with or without CMD. GLS, at baseline, was significantly lower in patients with CMD (-16.7±3.77 vs. -17.9±3.75 - p<0.01). We observed a different response to dipyridamole stress echocardiography, between the two groups: GLS significantly increased up to peak dose in patients without CMD (from -17.9±3.75 to -19.5±4.12 - p<0.01), whereas on the other hand, a significant decrease from rest to peak dose was observed in patients with CMD (from -16.7±3.77 to -15.4±4.21- p<0.01). There was a significant inverse correlation between CFR and delta GLS measured at rest and after dipyridamole peak dose (r = -0.83 - p<0.01). Conclusions: GLS analysis, performed by comparing dipyridamole peak-dose with baseline values, shows that in patients with CMD there is a different response of left ventricular myocardiim to stress test. It could be assumed that the inverse correlation between CFR and delta GLS reflects a progressive subclinical worsening of left ventricular myocardial function in these patients. Larger studies could confirm our data.

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