Impact of delayed ventricular wall area ratio on pathophysiology of mechanical dyssynchrony: implication from single-ventricle physiology and 0D modeling

Yohsuke Hayama,Hideo Ohuchi,Kenichi Kurosaki,Masaru Sugimachi,Aya Miyazaki,Jun Negishi,Toru Kawada,Shuji Shimizu,Heima Sakaguchi,Osamu Yamada

doi:10.1186/s12576-020-00765-y

Yohsuke Hayama, Hideo Ohuchi + Show 8 more

Open Access

PDF Available

https://doi.org/10.1186/s12576-020-00765-y

Copy DOI

Export

Save

Cite

Abstract
Highlights/Summary
Full-Text PDF
Similar Papers

Abstract

Listen

Electrical disparity can induce inefficient cardiac performance, representing an uncoordinated wall motion at an earlier activated ventricular wall: an early shortening followed by a systolic rebound stretch. Although regional contractility and distensibility modulate this pathological motion, the effect of a morphological factor has not been emphasized. Our strain analysis in 62 patients with single ventricle revealed that those with an activation delay in 60–70% of ventricular wall area suffered from cardiac dysfunction and mechanical discoordination along with prolonged QRS duration. A computational simulation with a two-compartment ventricular model also suggested that the ventricle with an activation delay in 70% of the total volume was most vulnerable to a large activation delay, accompanied by an uncoordinated motion at an earlier activated wall. Taken together, the ratio of the delayed ventricular wall has a significant impact on the pathophysiology due to an activation delay, potentially highlighting an indicator of cardiac dysfunction.

Highlights

And mechanically synchronous wall motion is essential for efficient cardiac performance
In an anatomically normal left ventricle, the left bundle branch block (LBBB) can induce an uncoordinated septal motion known as a septal flash, which is characterized by an early shortening during the isovolumic contraction period followed by a rebound stretch during the ejection period
Patients with LBBB have a worse prognosis than those with non-specific intraventricular conduction delay or with right bundle branch block [3, 4], which indicates that the uncoordinated motion of the regional myocardium is a key indicator of heart failure associated with mechanical dyssynchrony [5,6,7]

Summary

Introduction

And mechanically synchronous wall motion is essential for efficient cardiac performance. The disparity of electrical activation causes a time delay in regional peak contraction, and back-and-forth shortening and stretching of the regional myocardium, termed “mechanical discoordination”. In an anatomically normal left ventricle, the left bundle branch block (LBBB) can induce an uncoordinated septal motion known as a septal flash, which is characterized by an early shortening during the isovolumic contraction period followed by a rebound stretch during the ejection period. Patients with LBBB have a worse prognosis than those with non-specific intraventricular conduction delay or with right bundle branch block [3, 4], which indicates that the uncoordinated motion of the regional myocardium is a key indicator of heart failure associated with mechanical dyssynchrony [5,6,7]. Regional contractility [8] and diastolic property [9] were reported to modulate the pathophysiology of mechanical discoordination

Methods

Discussion

Conclusion