Mustafa Akçakoyun

Objective No data exist on the functional relevance of collateral vessels in patients undergoing percutaneous coronary intervention (PCI). Also, the subtle eff ects of improved collateral fl ow on right ventricular (RV) function are diffi cult to assess. However, novel echocardiographic approaches like tissue-Doppler imaging (TDI) and two-dimensional speckle-tracking echocardiography (2DSTE) can quantify RV regional myocardial function. We hypothesized that these techniques may help delineate revascularization therapy-induced changes in regional RV contractility that escape clinical routine studies. Methods This study was a prospective registry of consecutive patients undergoing PCI for a collateral supplying artery. All included patients underwent standard echocardiography with TDI and 2DSTE to assess RV function before successful PCI and it was repeated after 24 hours and 1 month. Results There were no signifi cant changes in either the RV systolic myocardial velocities, or the tricuspid annular plane systolic excursion values. However, RV free wall longitudinal strain/systolic strain rate values showed a signifi cant increase 24 hours after PCI when compared to baseline (–25.9 ± 6.8% vs. –21.5 ± 6.6%, P< 0.001 and –2.18 ± 0.40/s vs. –1.64 ± 0.41/s, P< 0.001, respectively). Also, the improvement of RV function was further suggested by the tendency of RV isovolumic acceleration to be higher when compared with baseline at 1 month of follow-up (2.49 ± 0.7 m/s2 vs. 2.15 ± 0.6 m/s2, P= 0.056). Conclusion Both TDI-derived isovolumic acceleration and 2DSTE-derived strain/strain rate produced a similar picture with respect to the change in RV contractile function. However, 2DSTE indicated a much more pronounced and earlier improvement of systolic function; therefore, 2DSTE could be included in future studies that involve functional relevance of collateral vessels.

Isovolumic acceleration assessed by tissue Doppler imaging has been proposed as a preload-independent indicator of left ventricular contractility. We investigated the utility of isovolumic acceleration in the prediction of preclinical right and left ventricular systolic dysfunction in hypertensive and obese subjects. Seventy-eight obese subjects (BMI >30 kg/m2; 57 women, 21 men; mean age 51±8 years) were prospectively enrolled. Fifty patients (64.1%) had hypertension and 33 patients (42.3%) had diabetes mellitus. All the subjects were assessed by conventional and tissue Doppler echocardiography. Myocardial velocities of the left ventricular septal and lateral mitral annulus and lateral tricuspid annulus were determined. Isovolumic contraction wave was defined as the preceding wave of the systolic wave that began before the peak of the R wave on the electrocardiogram. Myocardial isovolumic acceleration was measured by dividing the peak velocity by the time passed from the onset of the wave (zero-crossing) during isovolumic contraction to the peak velocity of the wave. Waist circumference was in positive correlation with left ventricular end-systolic (r=0.22, p=0.047) and end-diastolic (r=0.384, p=0.001) diameters, and in negative correlation with the peak systolic velocity of the tricuspid annulus (r=-0.311, p=0.006). Although hypertensive and normotensive (n=28) obese subjects had similar myocardial velocities, lateral tricuspid annular isovolumic acceleration (p=0.027), septal isovolumic acceleration (p=0.026), and septal isovolumic contraction myocardial velocity (p=0.018) were significantly lower in hypertensive patients. Isovolumic acceleration and isovolumic contraction myocardial velocity analysis may be useful in the diagnosis of subclinical left and right ventricular dysfunction in hypertensive obese patients.