Early right ventricular dysfunction after primary percutaneous coronary intervention in anterior versus isolated inferior myocardial infarction assessed by tissue Doppler imaging and speckle tracking echocardiography

From the physiological point of view, given the distribution of the perfusion territories of the major epicardial coronary arteries, inferior MI in most cases is due to RCA stenosis, which supplies both the RV free wall and the base of the interventricular septum and would thus affect most RV functional measurements while anterior MI is usually due to LAD artery stenosis, which does not significantly contribute to RV perfusion other than the RV apex when the LAD artery wraps around the apex [15]. Hence, RV dysfunction is more common in inferior LV infarction due to similar vascularization. However, the opposite occurs. The lower EF in the anterior MI group may drive the results finding of the association between RV dysfunction and anterior MI. EF was independently correlated to the RV dysfunction parameter of the LV infarction site. Our study revealed more RV dysfunction in anterior MI than inferior MI due to the synchronous LV and RV mechanical dysfunction based on the Torrent-Guasp model. Presumably, patients with anterior MI had an overall worse myocardial involvement as demonstrated by the worse LVEF and left ventricular end-diastolic diameter (LVEDD). Therefore, as demonstrated by previous studies, RV involvement is more present in the first group as it is representative of a more extensive disease. Moreover, a significant percentage of patients with non-culprit lesions with severe stenosis was found in both groups (20% vs. 34% in the inferior vs. anterior MI group, respectively, p < 0.0001), which may be a confounding factor in RV function evaluation.

LV systolic function and LVEF by Simpson’s method were highly significantly lower in the anterior MI group compared to the inferior MI group (p < 0.0001). Additionally, LV filling pressure was significantly higher in the anterior MI group (p < 0.001). This data was concordant with Abtahi et al. [15] who compared RV function in 60 patients, including 25 in group 1 and 35 in group 2 (acute myocardial infarction). Synchronous LV and RV mechanical dysfunction may be explained by the Torrent-Guasp model as the helical ventricular myocardial band encircles the right and left ventricles with transversely oriented circular myocardial fibers within a basal loop, while intermingled with two differently oriented oblique fibers, directed from right to left within the sub-endocardial muscle and from left to right within the sub-epicardial muscle, crisscross within the interventricular septum and connect in the apex of the heart. The cross-striation of oblique fibers in the ventricular septum increases septal twisting motion, which benefits both RV and LV performance [16].

LVEDD was significantly higher in the anterior MI group compared to the inferior MI group although both were within the normal range (p < 0.05). These data were concordant with Korup et al. [17] who examined 35 consecutive patients who were admitted to the hospital with the first episode of anterior or inferior STEMI and revealed increased end-systolic and end-diastolic measurements as early as 3 h after onset of symptoms in both groups, although LV dilatation was more pronounced in the anterior MI group. Slippage of necrotic myofibrils causing stretching of the infarct zone is caused by early LV dilatation.

RA and RV dimensions and RA diameter were significantly higher in the anterior MI group compared to the inferior MI group (p < 0.001). RV diameter was significantly higher in the anterior MI group compared to the inferior MI group although RV diameter was higher than the normal range in both groups (p < 0.05). These data were discordant with Abtahi et al. [15] who observed no significant difference between patients with anterior MI and inferior MI regarding RV and RA diameters. This could be explained by more RV involvement in the first group as it is representative of a more extensive disease. Moreover, a significant percentage of patients with non-culprit lesions had severe stenosis (20% vs. 34% in the inferior vs. anterior MI groups, respectively, p < 0.0001).

RV systolic function and TAPSE were significantly lower in the anterior MI group compared to the inferior MI group (p < 0.05). TAPSE was below the normal value in the anterior MI group while within the normal range in the inferior MI group. These data are concordant with Keskin et al. [18] who studied RV functions in 350 patients with first-time anterior STEMI and revealed significant RV systolic function reduction, including TAPSE. The TAPSE reduction in the anterior STEMI group is explained by the positive correlation between TAPSE and LVEF regardless of the RV systolic functions. Thus, the concept of ventricular interdependence shown in experimental models is an important explanatory factor in the relationship between TAPSE and LVEF.

MPI of RV (RMPI) by pulsed and tissue Doppler was significantly higher in the anterior MI group and normal in the inferior MI group with a significant difference between both groups (by PW, p = 0.00; by TDI, p = 0.006). These data are concordant with Ozturk et al. [19] who revealed a significant increase in this index after anterior STEMI.

The systolic velocity of the lateral wall of RV by tissue Doppler (S′) was significantly lower in the anterior MI group compared to the inferior MI group (p = 0.008). These data are concordant with Hsu et al. [20] who revealed lower RV annular velocities, including S′ in the anterior STEMI group compared to the inferior STEMI group. Hsu et al. [20] revealed that RV systolic functions might be affected regardless of the infarction site in patients with a first acute ST-elevation MI not associated with RV infarction, in agreement with our findings regarding RV systolic functions. Furthermore, he noted a depressed global systolic RV function in those with anterior MI.

RV systolic functions have a multitude of factors and are strongly dependent on LV function and shape and septal motion. Additionally, the unique overlapping nature of territories of coronary arteries and the variable patterns between different patients can explain these correlations.

RV diastolic function and tricuspid E/A ratio were normal in both groups with no significant difference (p = 0.096). However, lateral E′ was significantly lower in the anterior MI group compared to the inferior MI group (p = 0.005) while no significant difference between both groups regarding lateral E/e′ (p = 0.185). This data is in disconcordant with the findings of Hsu et al. [20], where RV diastolic dysfunction was reported in patients with inferior infarction, whereas Abtahi et al. [15] reported no significant differences between both groups regarding RV diastolic functions.

The tricuspid E/E′ ratio and diastolic SR are commonly utilized to assess RV diastolic function.

Demirkol et al. [21] revealed a substantial link between the tricuspid E/e′ ratio, RA volume, and hemodynamic parameters in the tricuspid valve. The tricuspid E/E′ ratio predicts cardiac events and increased mean arterial pressure as a reliable measure of RV filling pressure. An E/e′ ratio of > 6 exhibited good sensitivity and specificity in identifying the mean RA pressure of 10 mmHg.

The systolic velocity of the lateral wall of RV, as assessed by tissue Doppler (S′), was significantly lower in the anterior MI group compared to the inferior MI group (p = 0.008). These data are concordant with Hsu et al. [20] who reported lower RV annular velocities, including S′ in the anterior STEMI group compared to the inferior STEMI group. Hsu et al. [20] revealed that RV systolic functions might be affected regardless of the infarction site in patients with a first acute STEMI not associated with RV infarction, in agreement with our findings regarding RV systolic functions. Furthermore, he noted depressed global systolic RV function in patients with anterior infarction.

Concerning the RV diastolic function, the tricuspid E/A ratio was normal in both groups with no significant difference (p = 0.096). However, lateral E′ was significantly lower in the anterior MI group compared to the inferior MI group (p = 0.005) while no significant difference between both groups regarding lateral E/e′ (p = 0.185). These data are discordant with the findings of Hsu et al. [20], where RV diastolic dysfunction was reported in patients with inferior MI, whereas Abtahi et al. [19] reported no significant differences between both groups regarding RV diastolic functions. This could be explained by a significant percentage of patients with non-culprit lesions with severe stenosis (20% vs 34% in the inferior vs. anterior MI groups, respectively, p < 0.0001).

RV free wall tissue velocity was lower than the average with no significant difference between both groups. RV strain was significantly lower in the anterior MI group compared to the inferior MI group (p < 0.001). RV septal strain was significantly lower in the anterior MI group compared to the inferior MI group (p < 0.001 and p = 0.018, respectively), as well as the RV free wall strain (p < 0.001). RV-GLS was significantly lower in the anterior MI group compared to the inferior MI group (p = 0.009).

RV systolic function using strain assessed by TDI and speckle tracking is disconcordant with that of Huttin et al. [22] who demonstrated reduced RV strain values in all MI sites; however, it was more pronounced in inferior than anterior MI. In contrast, the septal strain was the same in both groups. Notably, Huttin et al. [22] did not exclude patients with electrocardiographic evidence of RV STEMI.

Mohamed et al. [23] excluded patients with electrocardiographic evidence of RV infarction and enrolled 80 patients with anterior STEMI who were subjected to PPCI. RV functions were assessed using strain by speckle tracking, which revealed a significant relationship between RV affection and anterior STEMI, which was consistent with our findings.

Nourian et al. [24] evaluated RV systolic and diastolic functions between inferior STEMI without RV involvement and inferior STEMI with RV infarction and revealed that the RV-GLS in the inferior STEMI group without RV infarction was normal, which is in concordant with our findings.

Our results showed a significant positive correlation between EF and TAPSE in the anterior (r = 0.296, p = 0.37) and inferior MI groups (r = 0.467, p = 0.001). Antoni et al. [25] revealed a substantial positive correlation between LVEF and TAPSE, regardless of the site of the STEMI in patients with acute STEMI, similar to our findings.

留言 (0)

沒有登入
gif