Current Concepts in Pacing 2010–2011: The Right and Wrong Way to Pace

Abstract

Over five decades have passed since the first permanent cardiac pacemakers were introduced into clinical medicine. Evolving technology and falling costs have demanded adaptation to clinical practice and implantation trends and, with the advent of evidenced-based medicine, the specific roles and benefits of individual pacemaker technologies have never been so carefully scrutinized. Pacing mode choice continues to be a subject of great controversy, and there are great regional variations in practice. We believe that single chamber atrial pacing use (AAI/R) has become an anachronism that should generally be abandoned (obviously with rare exceptional cases) and be replaced by dual chamber pacemakers (DDD/R) equipped with modern pacing algorithms that minimize patient exposure to ventricular pacing. Also, in patients with atrioventricular (AV) block, randomized clinical trials have failed to show improvement in clinically relevant outcomes such as mortality, stroke, and heart failure, particularly in the elderly, which has led some to advocate that DDD/R devices should never be offered to elderly AV block patients. However, we believe that the elderly, like the young, come in many "shapes and sizes" and individualized medicine compels us to consider each pacemaker candidate as unique. Implanting DDD/R devices in chronologically older, yet physiologically younger, patients is justifiable and good medical practice. Where right ventricular (RV) pacing is necessary and unavoidable, physicians should consider routinely placing RV leads on the RV mid- or outflow tract septum because these location are as good, if not better, for patients than the current practice of RV apical lead placement. In patients with AV block and asymptomatic yet moderate to severely depressed left ventricular systolic function, primary cardiac resynchronization therapy (CRT) should be strongly considered. Compelling clinical trial evidence does not yet exist to indicate that CRT should be the standard of care in patients with AV block and intact left ventricular systolic function. Right ventricular septal lead placement remains a reasonable option.

Assessment of Ventricular Pacing in the Setting of an Institutional Improvement Program: Insights into Physiological Pacing

“…15,16 For patients with ventricular pacing dependency, septal (or outflow tract) pacing is proven to be efficient, 4 also cardiac resynchronization therapy can be evoked in selected patients with mild to moderate heart failure 10 and has proven to be beneficial and cost-effective. As a result of decreasing ventricular pacing, there is less risk of detrimental effects, 1619–20 including ventricular remodeling and pacing-induced cardiomyopathy.…”

Computational optogenetics: A novel continuum framework for the photoelectrochemistry of living systems

“…Pacemakers deliver electrical stimuli via implanted pacing leads that are in contact with the heart muscle. Although permanent pacemaker implantation is a standard procedure today, pacing lead placement continues to be a subject of great controversy [30]. Choosing the optimal pacing site is becoming more challenging [36], in particular in view of novel stimulation strategies such as single chamber, dual chamber, and biventricular pacing.…”

“…We virtually inject our genetically engineered, light sensitive cardiac cells into different regions of the heart [30], and model all other cells as conventional cardiac muscle cells [43, 47]. The former group of cells possesses the additional channelrhodopsin current I ChR2 , while the latter does not.…”