Can Segmental Wall Motion Abnormalities Be Present in Chronic Stable Angina?
Yes, segmental wall motion abnormalities can definitely be present in patients with chronic stable angina, even without prior myocardial infarction, and they represent either chronic myocardial hibernation from inadequate collateral flow reserve or repeated episodes of stunning from recurrent ischemia.
Pathophysiology of Wall Motion Abnormalities in Stable Angina
Chronic regional wall motion abnormalities occur in stable angina patients through two distinct mechanisms:
Myocardial hibernation develops when collateral-dependent myocardium has inadequate flow reserve despite near-normal resting perfusion, leading to chronically depressed contractile function with profound structural changes including cellular swelling, loss of myofibrillar content, and glycogen accumulation 1
Repeated myocardial stunning results from recurrent ischemic episodes that cause prolonged contractile dysfunction persisting well beyond the resolution of ischemia, with wall motion abnormalities potentially lasting 24 hours or longer after anginal episodes 2
In patients with noninfarcted collateral-dependent myocardium, immature collaterals fail to provide adequate flow reserve, and these segments exhibit chronically depressed wall motion despite nearly normal resting flow and oxygen consumption 1
There is a significant inverse correlation (r = -0.85) between the severity of wall motion abnormality and collateral flow reserve, meaning worse collateral development predicts more severe dysfunction 1
Clinical Detection and Reversibility
These wall motion abnormalities are reversible with revascularization, confirming they represent viable but dysfunctional myocardium:
Regional wall motion scores improve significantly after coronary revascularization, from 3.8 ± 1.3 to 0.8 ± 0.9 (p < 0.005), demonstrating that the dysfunction is not due to scar tissue 1
After successful PTCA in stable angina patients with abnormal regional wall motion, summed segment scores improve from 4.5 ± 2.5 to 1.6 ± 2.1 (p < 0.01), with 49 of 69 hypokinetic segments becoming normal and 10 of 12 akinetic segments becoming hypokinetic 3
Even in patients without previous myocardial infarction, wall motion abnormalities are present and reversible, with summed segment scores decreasing from 4.2 ± 3.4 to 0.86 ± 1.6 (p < 0.05) after PTCA 3
Regional outward movement during early systole and abnormal inward wall movement during isovolumic relaxation can occur in angina patients with normal coronary arteriograms, affecting the apex or inferior surface in approximately 22% of such patients 4
Guideline-Based Assessment Recommendations
Guidelines specifically address when to assess for segmental wall motion abnormalities in stable angina:
Do NOT routinely assess left ventricular ejection fraction and segmental wall motion by echocardiography or radionuclide imaging in patients with a normal ECG, no history of MI, and no evidence of congestive heart failure 5
DO assess left ventricular ejection fraction and segmental wall motion by echocardiography or radionuclide imaging in patients with new or worsening congestive heart failure or evidence of intervening MI by history or electrocardiography 5
Assessment of myocardial viability using dobutamine stress echocardiography is indicated for planning revascularization in patients with chronic LV dysfunction, as improvement of segmental function during dobutamine indicates contractile reserve and predicts likelihood of improved ventricular function after revascularization 5
Clinical Implications for Management
The presence of wall motion abnormalities in stable angina has important prognostic and therapeutic implications:
Stress echocardiography demonstrating wall-motion abnormality involving more than 2 segments developing at low dose dobutamine (≤10 mcg/kg/min) or at low heart rate (<120 beats/min) indicates high risk with greater than 3% annual mortality rate 5
Stress-induced extensive ischemia on echocardiography similarly indicates high-risk status requiring more aggressive management 5
In patients with unstable angina and normal or nonspecific ECG changes, echocardiography can reveal reversible segmental wall motion abnormalities during pain that are characteristic of transient ischemia and identify the coronary territory involved and size of area at risk 5
Common Pitfalls to Avoid
Critical considerations when interpreting wall motion abnormalities in stable angina:
Do not assume that wall motion abnormalities always indicate prior infarction—they frequently represent viable but dysfunctional myocardium that will improve with revascularization 1, 3
Recognize that resting wall motion abnormalities may be present despite normal resting myocardial blood flow, as the dysfunction results from inadequate flow reserve rather than resting hypoperfusion 1
Avoid ordering repeated echocardiography or radionuclide imaging in less than 3 years in patients with no change in clinical status and low estimated annual mortality rate, as this provides no clinical benefit 5
Remember that wall motion abnormalities from stunning can persist for 24 hours or longer after anginal episodes, so timing of assessment relative to symptoms matters 2