Coronary Artery Blood Flow in Acute Ischemic Stroke

Background: Stroke is the third leading cause of death in the USA. Cardiac disturbances are common following stroke. We examined the influence of stroke and its severity on the coronary artery blood velocity and flow.

Methods: This prospective study included thirty consecutive patients with acute ischemic cerebrovascular disease. Age 65.6±13 years, 47% women, the group was studied and compared to a matched control group of 74 subjects without evidence of cardiovascular disease. Beside clinical evaluation using National Institutes of Health Stroke Scale (NIHSS), all subjects had completed a transthoracic Doppler echocardiographic study including sampling of blood velocity in the left anterior descending coronary artery (LAD).

Results: Compared to the control group, patients with stroke had higher LAD velocity parameters including higher diastolic velocity integral (11.9±4.94 vs 9.1±3.3cm, p=0.006), and significantly higher systolic velocity parameters as well as more prolonged diastolic deceleration times, which may indicate higher LAD flow in the setting of stroke. Ventricular dimensions and wall thicknesses parameter were similar in the two groups. Patients with mild Stroke (NIHSS≤4) had higher heart rate and higher systemic arterial diastolic blood pressure (87.6±14.7 vs 72.7±6.52mmHg, p=0.01) compared to those with severe stroke (NIHSS≥5), they also had thinner ventricular septum (1.21±0.1 vs 1.345±0.1cm, p=0.025) and had higher systolic LAD velocity (19±7.77 vs 14.2±3.21cm/sec, p=0.028). Other parameters, including diastolic LAD velocity parameters, were similar between the two groups.

Conclusion: In the setting of stroke, coronary flow parameters are increased, although this increment seems not to correlate with the severity of the stroke. Despite higher diastolic blood pressure found in patients with mild stroke, the coronary flow parameters found to be similar to those with severe stroke implying higher coronary resistance in the latter. Cardiac hypertrophy may decrease LAD systolic velocities probably due to increased intramural perivascular pressure during systole.