Changes in the Velocities of the Mitral Annulus Assessed by Tissue Doppler Imaging with Respect to the Cardiac Rhythm

An 84-year-old man with hypertensive heart disease was headed for electrical cardioversion (ECV) because of atypical atrial flutter with 2:1 conduction. Transthoracic echocardiography revealed normal systolic function, slight left ventricular hypertrophy, and a left atrial diameter of 42 mm.

In order to assess the systolic and diastolic velocities of the mitral annulus before and after ECV for scientific purposes, a pulsed-waved tissue Doppler imaging (TDI) analysis was performed. The patient showed an S′ velocity of 10 cm/sec and an E′ velocity between 18 and 22 cm/sec at the septal mitral annulus, which usually shows lower velocities than the lateral mitral annulus.

During TDI data acquisition, the sinus rhythm was spontaneously restored for 5 beats ([Fig. 1]). This change in rhythm caused an immediate deterioration of the diastolic velocity E′ to 7.5 – 10 cm/sec, a new onset of an A′-wave with a velocity of 12.5 cm/sec, and a slightly increased systolic velocity S′ with a changed shape ([Fig. 2]). Interestingly, the summation of E′ and A′ during sinus rhythm was as high as the E′-velocity during atrial flutter, when the patient had no A′-wave.

Fig. 1 ECG showing atrial flutter with 2:1 conduction in the upper panel and the spontaneous restoration of sinus rhythm for 5 beats in the lower panel (25 mm/sec).

Abb. 1 Elektrokardiogramm mit Nachweis eines Vorhofflatterns mit einer 2:1-Überleitung (obere Zeile) und spontaner Konversion in einen Sinusrhythmus für 5 Schläge (untere Zeile; 25 mm/s).

Fig. 2 TDI analysis of the septal mitral annulus showing an increased systolic velocity (S’), but a decreased E’ and A’ velocity after the spontaneous restoration of sinus rhythm (arrow).

Abb. 2 Gewebedoppler-Analyse der systolischen und diastolischen Mitralring-Geschwindigkeiten vor und nach spontaner Konversion in den Sinusrhythmus (Pfeil).

Only minimal data is available about the reliability and usefulness of a TDI analysis in atrial fibrillation or atrial flutter (Sohn DW et al. J Am Soc Echocardiogr 1999; 12: 927 – 931). It has been shown that TDI is useful for the detection of impaired left ventricular relaxation and the estimation of filling pressures in atrial fibrillation (Butz T et al. Dtsch Med Wochenschr 2008; 133: 399 – 405). It has been previously demonstrated that the peak systolic velocity was decreased immediately after ECV of atrial fibrillation on the one hand, but there were no significant changes after ECV of atrial flutter on the other hand (Fung KC et al. J Am Soc Echocardiogr 2003; 16: 656 – 663). In an other study, no differences in peak myocardial early velocity (E′), deceleration time of E`, and myocardial isovolumic relaxation time measured from mitral lateral annulus before, 24 hours after, and one month after ECV were found (Melek M et al. Echocardiography 2007; 24: 34 – 39).

In contrast to these findings, it has been demonstrated that transthoracic atrial and transesophageal left atrial appendage strain and strain rate, which are quantitative measures of atrial function, were reduced after cardioversion, but recovered subsequently within 10 days. However, it has been recently shown that patients with chronic atrial fibrillation have persistent segmental left atrial dysfunction even 6 months after restoration and maintenance of sinus rhythm even though right atrial velocities appear to normalize. This differential recovery indicated that left atrial function remains subnormal in patients with chronic atrial fibrillation despite maintenance of sinus rhythm, suggesting underlying atrial myopathy or fibrosis as a consequence or even cause of atrial fibrillation (Boyd AC et al. Eur J Echocardiogr 2008; 9: 12 – 17).