Global and regional wall motion abnormalities of pacing-induced heart failure assessed by multi-detector row CT: a patient and canine model study

Altered myocardial characteristics of the preexcited segment in Wolff-Parkinson-White syndrome: A pilot study with cardiac magnetic resonance imaging

Purpose

The preexcited myocardium of Wolff-Parkinson-White (WPW) syndrome would have different characteristics from normal myocardium and these findings might be related to persistent left ventricular systolic dysfunction. We evaluated myocardial tissue characteristics at the preexcited segment in adult WPW syndrome patients and their implicated findings.

Methods

For this prospective study, we enrolled 22 adult WPW syndrome patients (16 male, mean 45.4 ± 17.8 years) with echocardiographic findings of regional wall motion abnormality in our electrophysiology clinic. Of these patients, 14 underwent radiofrequency ablation before cardiac magnetic resonance imaging. All patients underwent cardiac magnetic resonance imaging including cine and late gadolinium enhancement. The ventricular morphology, function and myocardial characteristics of the preexcited segment were analyzed.

Results

A relatively high prevalence of late gadolinium enhancement (9/22, 40.9%) was observed exclusively at the basal septum. The septal accessory pathway was significantly more prevalent in patients with late gadolinium enhancement (P = 0.011). The prevalences of regional myocardial wall thinning and regional akinesia were significantly higher (P = 0.001 for both) and left ventricular function was significantly decreased in patients with late gadolinium enhancement (P < 0.001). In addition, there were no significant relationships between radiofrequency ablation and regional akinesia (P > 0.999), regional myocardial wall thinning (P > 0.999), late gadolinium enhancement (P = 0.662) and low ejection fraction (P > 0.999).

Conclusion

Myocardial fibrosis was observed at the preexcited myocardium of adult WPW syndrome patients with septal accessory pathway, which could accompany regional akinesia and regional myocardial wall thinning and might be related to persistent left ventricular systolic dysfunction even after radiofrequency ablation.

Detecting Regional Myocardial Abnormalities in Patients With Wolff-Parkinson-White Syndrome With the Use of ECG-Gated Cardiac MDCT

OBJECTIVE

Myocardial dyskinesia caused by the accessory pathway and related reversible heart failure have been well documented in echocardiographic studies of pediatric patients with Wolff-Parkinson-White (WPW) syndrome. However, the long-term effects of dyskinesia on the myocardium of adult patients have not been studied in depth. The goal of the present study was to evaluate regional myocardial abnormalities on cardiac CT examinations of adult patients with WPW syndrome.

MATERIALS AND METHODS

Of 74 patients with WPW syndrome who underwent cardiac CT from January 2006 through December 2013, 58 patients (mean [± SD] age, 52.2 ± 12.7 years), 36 (62.1%) of whom were men, were included in the study after the presence of combined cardiac disease was excluded. Two observers blindly evaluated myocardial thickness and attenuation on cardiac CT scans. On the basis of CT findings, patients were classified as having either normal or abnormal findings. We compared the two groups for other clinical findings, including observations from ECG, echocardiography, and electrophysiologic study.

RESULTS

Of the 58 patients studied, 16 patients (27.6%) were found to have myocardial abnormalities (i.e., abnormal wall thinning with or without low attenuation). All abnormal findings corresponded with the location of the accessory pathway. Patients with abnormal findings had statistically significantly decreased left ventricular function, compared with patients with normal findings (p < 0.001). The frequency of regional wall motion abnormality was statistically significantly higher in patients with abnormal findings (p = 0.043). However, echocardiography documented structurally normal hearts in all patients.

CONCLUSION

A relatively high frequency (27.6%) of regional myocardial abnormalities was observed on the cardiac CT examinations of adult patients with WPW syndrome. These abnormal findings might reflect the long-term effects of dyskinesia, suggesting irreversible myocardial injury that ultimately causes left ventricular dysfunction.