Dynamic handgrip exercise for the detection of myocardial ischemia using fast Strain-ENCoded cardiovascular magnetic resonance

Figures

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  Fig. 1. DHE and fSENC imaging. Schematic visualization of the both-sided, DHE at approx. Fifty precentage of MVC and a frequency of 80/min including fSENC acquisition at rest and during DHE. The comparison between fSENC at rest and after DHE of the apical slice in this example shows an impairment of LS after DHE of the inferior apical wall. DHE and fSENC acquisition was integrated into CMR routine protocol and was performed before pharmacological stress. DHE dynamic handgrip exercise, fSENC fast Strain-ENCoded imaging, MVC maximum voluntary contraction, LS longitudinal strain

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  Fig. 2. Overview of left ventricular strain directions and their corresponding CMR planes. In contrast to commonly used CMR post-processing tools like feature tracking or speckle-tracking echocardiography, short-axis fSENC slices are required for the assessment of LS, long-axis fSENC slices are required for CS. RS cannot be assessed using fSENC. In this DHE-fSENC study, only LS was assessed. LS longitudinal strain, CS circumferential strain, RS radial strain, LAX long axis, SAX short axis, fSENC fast Strain-ENCoded imaging, DHE dynamic handgrip exercise, CMR cardiovascular magnetic resonance

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  Fig. 3. Flowchart of patient recruitment. Three hundred thirty nine patients agreed to the handgrip study. In total, 79 patients had to be excluded mainly because of technical reasons including bad CMR image quality or failed triggering/bad quality of fSENC sequence leading to a final study population of 260 patients. CMR cardiac magnetic resonance imaging, DHE dynamic handgrip exercise, fSENC fast strain-encoded imaging, ICA invasive coronary angiography

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  Fig. 4. Stress test duration of DHE-fSENC. The duration of DHE-fSENC was significantly reduced compared to standard pharmacological stress tests (p<0.001). DHE dynamic handgrip exercise, fSENC fast Strain-ENCoded imaging

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  Fig. 5. (B) DHE-fSENC: longitudinal strain response. Comparison of LS at rest and during DHE. In ischemic segments, longitudinal strain was significantly impaired during DHE. In contrast, LS was more pronounced during DHE in non-ischemic segments. DHE dynamic handgrip exercise, LS longitudinal strain, SEM standard error of the mean

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  Fig. 6. Examples. (A) Negative stress test. 61-year-old, male patient. Progressive dyspnea without typical angina. ICA revealed proximal LAD stenosis with 50% lumen narrowing. Adenosine-perfusion was rated negative. During DHE, the HR increased from 60/min to 98/min, GLS was more pronounced after DHE, from −16.7% to −20.2%. DHE-fSENC was rated negative for ischemia. (B) Positive stress test. 75-year-old, male patient. No dyspnea or typical angina. Former resuscitation during non-ST-elevation myocardial infarction due to LAD stenosis 6 months before. Residual stenosis of LCx (75%). Adenosine-perfusion was rated positive lateral midventricular (2 segments). During DHE HR increased from 54/min to 83/min, GLS slightly increased from −19.0% to −19.5%. In the qualitative analysis of DHE-fSENC a worsening of LS lateral midventricular was observed, similar to adenosine-perfusion – DHE-fSENC was rated positive. (C) “False-positive” stress test. 57-years-old, female patient. Three months before - after progressive, typical angina –PCI including the insertion of a drug-eluting stent into the distal RCA was performed. The patient was referred to stress CMR for residual LCx and LAD stenoses (both…