QRS Duration During Follow-Up of Tetralogy of Fallot: How Valuable is it? Analysis of ECG Changes in Relation to Pulmonary Valve Implantation

Right ventricular dilatation score: a new assessment to right ventricular dilatation in adult patients with repaired tetralogy of Fallot

BACKGROUND

Patients with repaired tetralogy of Fallot (rTOF) experience long-term chronic pulmonary valve regurgitation resulting in right ventricular (RV) dilatation. According to current guidelines, the evaluation of patients with rTOF for RV dilatation should be based on cardiac magnetic resonance (CMR). However, for many asymptomatic patients, routine CMR is not practical. Our study aims to identify screening methods for CMR based on echocardiographic data, with the goal of establishing a more practical and cheap method of screening for severity of RV dilatation in patients with asymptomatic rTOF.

METHODS

Thirty two rTOF patients (mean age, 21(10.5) y, 21 males) with moderate to severe pulmonary regurgitation (PR) were prospectively recruited. Each patient received CMR and echocardiogram examination within 1 month prior to operation and collected clinical data, and then received echocardiogram examination at discharge and 3-6 months post-surgery.

RESULTS

RV moderate-severe dilatation was defined as right ventricular end-diastolic volume index (RVEDVI) ≥ 160 ml/m2 or right ventricular end-systolic volume index (RVESVI) ≥ 80 ml/m2 in 15 of 32 patients (RVEDVI, 202.15[171.51, 252.56] ml/m2, RVESVI, 111.99 [96.28, 171.74] ml/m2). The other 17 (RVESDI, 130.19 [117.91, 139.35] ml/m2, RVESVI = 67.91 [63.35, 73.11] ml/m2) were defined as right ventricle mild dilatation, i.e., RVEDVI < 160 ml/m2 and RVESVI < 80 ml/m2, and the two parameters were higher than normal values. Compared with the RV mild dilatation group, patients of RV moderate-severe dilatation have worse cardiac function before surgery (right ventricular ejection fraction, 38.92(9.19) % versus 48.31(5.53) %, p < 0.001; Left ventricular ejection fraction, 59.80(10.26) versus 66.41(4.15), p = 0.021). Patients with RV moderate-severe dilatation faced longer operation time and more blood transfusion during operation (operation time, 271.53(08.33) min versus 170.53(72.36) min, p < 0.01; Intraoperative blood transfusion, 200(175) ml versus 100(50) ml, p = 0.001). Postoperative RV moderate-severe dilatation patients have poor short-term prognosis, which was reflected in a longer postoperative hospital stay (6.59 [2.12] days versus 9.80 [5.10] days, p = 0.024) and a higher incidence of hypohepatia (0[0] % versus 4[26.7] %, p = 0.023). Patients with RV dilatation score > 2.35 were diagnosed with RV moderate-severe dilatation (AUC = 0,882; Sensitivity = 94.1%; Specificity = 77.3%).

CONCLUSIONS

RV moderate-severe dilatation is associated with worse preoperative cardiac function and short-term prognosis after PVR in rTOF patients with moderate to severe PR. The RV dilatation score is an effective screening method. When RV dilatation score > 2.35, the patient is indicated for further CMR examination and treatment.

Outcomes of Transcatheter Pulmonary Valve Replacement and Surgical Pulmonary Valve Replacement: A Cohort Analysis

Background

Transcatheter pulmonary valve replacement (TPVR) has become an alternative to surgical pulmonary valve placement (SPVR) for patients after tetralogy of Fallot repair. This study compared the outcomes of TPVR with those of SPVR.

Methods

We reviewed data from patients who underwent pulmonary valve replacement with a median of 2 years of follow-up.

Results

Between 2010 and 2021, 215 patients underwent pulmonary valve replacement (72 TPVR and 143 SPVR). The median size of the right ventricular end-diastolic volume index in the TPVR group was 165 mL/m2 (IQR, 136-190) and 184 mL/m2 (IQR, 163-230) in the SPVR group (P = .001). The median value of the maximum landing zone at the right ventricular outflow tract (RVOT) in patients with native RVOT was 26 mm (IQR, 24-28) in the 43 patients in the TPVR group and 31 mm (IQR, 28-34) in the 101 patients in the SPVR group (P < .001). The median size of the pulmonary valve implant for the native RVOT in the TPVR group was 29.0 mm (IQR, 26.0-29.0) and 24.0 mm (IQR, 24.0-24.0) in the SPVR group (P < .001). There were no deaths in the TPVR group and 8 deaths in the SPVR group (P = .041). Major complications and the length of hospitalization were lower in the TPVR group (P = .001). After 2 years, the mean decrease in QRS duration was 5 milliseconds (IQR, 1-14) in the TPVR group and 1 millisecond (IQR, -4 to 10) in the SPVR group (P = .006).

Conclusions

TPVR allows for larger implants, resulting in lower mortality, shorter hospital stays, and fewer major cardiac events. SPVR may be preferable in patients with larger (>30 mm) native RVOT and in those who require concomitant surgical procedures.

Inherited and Acquired Rhythm Disturbances in Sick Sinus Syndrome, Brugada Syndrome, and Atrial Fibrillation: Lessons from Preclinical Modeling

Rhythm disturbances are life-threatening cardiovascular diseases, accounting for many deaths annually worldwide. Abnormal electrical activity might arise in a structurally normal heart in response to specific triggers or as a consequence of cardiac tissue alterations, in both cases with catastrophic consequences on heart global functioning. Preclinical modeling by recapitulating human pathophysiology of rhythm disturbances is fundamental to increase the comprehension of these diseases and propose effective strategies for their prevention, diagnosis, and clinical management. In silico, in vivo, and in vitro models found variable application to dissect many congenital and acquired rhythm disturbances. In the copious list of rhythm disturbances, diseases of the conduction system, as sick sinus syndrome, Brugada syndrome, and atrial fibrillation, have found extensive preclinical modeling. In addition, the electrical remodeling as a result of other cardiovascular diseases has also been investigated in models of hypertrophic cardiomyopathy, cardiac fibrosis, as well as arrhythmias induced by other non-cardiac pathologies, stress, and drug cardiotoxicity. This review aims to offer a critical overview on the effective ability of in silico bioinformatic tools, in vivo animal studies, in vitro models to provide insights on human heart rhythm pathophysiology in case of sick sinus syndrome, Brugada syndrome, and atrial fibrillation and advance their safe and successful translation into the cardiology arena.