Haemodynamic changes during dobutamine stress echocardiography in patients with and without ischaemia

Coronary calcification with no flow limiting lesions: A potential cause for ischaemic dysfunction in syndrome X patients

Aim

Exertional angina in patients with no coronary flow limiting lesions remains a clinical puzzle. We aimed to assess the extent of coronary artery calcification (CAC) and its relationship to ventricular wall motion function using stress echocardiography in a group of patients limited by exertional angina, but no obstructive lesions.

Methods

We compared CT coronary calcium score (CACS) and dobutamine stress echocardiography in 55 patients (age 64.7 ± 7.7 years), divided into Group 1 (CACS ≤ 100) and Group 2 (CACS > 100). No patient had LV ejection fraction-EF < 55%, pulmonary hypertension, arrhythmia, renal failure or parathyroid disease. Multiple linear regression analysis was used to test the association between gender-standardized continuous echocardiographic parameters and patient groups adjusted for age, body surface area, osteoporosis and CV risk factors and CACS.

Results

At rest, LV long axis ‘subendocardial’ function was reduced (amplitude: β − 1.11 SD, p < 0.05, R² 0.6 and systolic velocity: β − 1.08 SD, p < 0.05, R² 0.44), left atrial (LA) indexed volume was raised (β 1.06 SD, p < 0.05, R² 0.37) and its systolic velocity decreased (β − 1.05 SD, p < 0.05, R² 0.35) in Group 2. With stress, wall motion score index increased (p < 0.05) and long axis disturbances worsened only in the same group. Multivariate analysis demonstrated clear relationship between ischaemic LV disturbances, reduced long axis amplitude, global longitudinal systolic strain and early diastolic strain rate. Resting and stress RV lengthening velocity also correlated with CAC score.

Conclusion

In symptomatic patients with no obstructive coronary lesions and with more than mild CAC, long axis disturbances and wall motion score index rise occur with stress, at the time of symptom development and correlate with severity of arterial calcification. These findings suggest CAC as a potential mechanism for coronary wall stiffness and consequently exertional ischaemic changes as a result of limited flow reserve.

Transposition complexes in the adult: a changing perspective

This study has shown the heterogeneous group of patients with discordant ventricular arterial relations, their management and problems encountered during follow up. Patients after surgery for transposition are still relatively young by cardiology standards and their problems continue to evolve; nevertheless the future is becoming clearer. However there are still important lessons to be learnt by continued and diligent observation and systematic, multicenter research. It is important to maintain a low threshold for thorough re-evaluation of patients whenever new symptoms are discovered. Indeed, patients should undergo regular detailed investigations at timely intervals. It is vital that this evolving group of adult patients, as with most patients emerging from a childhood with other congenital heart malformations, is managed by cardiologists fully trained in congenital heart disease.