Cardiac Pacing, Defibrillation and Resynchronization

Anatomy and physiology are the basis of human body functioning and as we have progressed in management of various diseases, we have understood that physiological intervention is always better than an anatomical one. For more than 50 years, a standard approach to permanent cardiac pacing has been an anatomical placement of transvenous pacing lead at the right ventricular apex with a proven benefit of restoring the rhythm. However, the resultant ventricular dyssynchrony on the long-term follow-up in patients requiring more than 40% ventricular pacing led to untoward side effects in the form of heart failure and arrhythmias. To counter such adverse side effects, a need for physiological cardiac pacing wherein the electrical impulse be transmitted directly through the normal conduction system was sought. His bundle pacing (HBP) with an intriguing alternative of left bundle branch pacing (LBBP) is aimed at restoring such physiological activation of ventricles. HBP is safe, efficacious, and feasible; however, localization and placement of a pacing lead at the His bundle is challenging with existing transvenous systems due to its small anatomic size, surrounding fibrous tissue, long-learning curve, and the concern remains about lead dislodgement and progressive electrical block distal to the HBP lead. In this article, we aim to take the reader through the challenging journey of HBP with focus upon the hardware and technique, selective versus nonselective HBP, indications and potential disadvantages, and finally the future prospects.

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Temporary Cardiac Pacing

Critical Care Medicine ◽

10.1097/00003246-199106000-00031 ◽

1991 ◽

Vol 19 (6) ◽

pp. 845

Author(s):

Peter Alagona

Keyword(s):

Cardiac Pacing

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Book Review: Resuscitation and Cardiac Pacing

Proceedings of the Royal Society of Medicine ◽

10.1177/003591576505800748 ◽

1965 ◽

Vol 58 (7) ◽

pp. 564-564

Author(s):

J P Shillingford

Keyword(s):

Cardiac Pacing

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Computational Analysis of Coronary Blood Flow: The Role of Asynchronous Pacing and Arrhythmias

Mathematics ◽

10.3390/math8081205 ◽

2020 ◽

Vol 8 (8) ◽

pp. 1205

Author(s):

Timur Gamilov ◽

Philipp Kopylov ◽

Maria Serova ◽

Roman Syunyaev ◽

Andrey Pikunov ◽

...

Keyword(s):

Heart Rate ◽

Blood Flow ◽

Coronary Blood Flow ◽

Long Qt Syndrome ◽

Premature Ventricular Contraction ◽

Cardiac Pacing ◽

Long Qt ◽

Computational Evaluation ◽

Qt Syndrome

In this work we present a one-dimensional (1D) mathematical model of the coronary circulation and use it to study the effects of arrhythmias on coronary blood flow (CBF). Hydrodynamical models are rarely used to study arrhythmias’ effects on CBF. Our model accounts for action potential duration, which updates the length of systole depending on the heart rate. It also includes dependency of stroke volume on heart rate, which is based on clinical data. We apply the new methodology to the computational evaluation of CBF during interventricular asynchrony due to cardiac pacing and some types of arrhythmias including tachycardia, bradycardia, long QT syndrome and premature ventricular contraction (bigeminy, trigeminy, quadrigeminy). We find that CBF can be significantly affected by arrhythmias. CBF at rest (60 bpm) is 26% lower in LCA and 22% lower in RCA for long QT syndrome. During bigeminy, trigeminy and quadrigeminy, respectively, CBF decreases by 28%, 19% and 14% with respect to a healthy case.

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