Postextrasystolic aortic pressure pulse response in coronary artery disease

Post-extrasystolic Blood Pressure Potentiation as a Risk Predictor in Cardiac Patients

For more than 100 years physicians have observed that heartbeats following extrasystolic beats are characterised by augmented myocardial contractility. This phenomenon was termed post-extrasystolic potentiation (PESP). In the 1970s it was first noted that PESP measured at the blood pressure level is typically pronounced in heart failure patients. Only recently, it was shown that PESP measured non-invasively as post-extrasystolic blood pressure potentiation was a strong and independent predictor of death in survivors of myocardial infarction and in patients with chronic heart failure. A similar parameter (PESPAfib) can be also assessed in patients with atrial fibrillation. PESP and PESPAfib can be understood as non-invasive parameters that indicate myocardial dysfunction. They have the potential to improve risk stratification strategies for cardiac patients.

Postextrasystolic potentiation. Do we really know what it means and how to use it?

Postextrasystolic potentiation (PESP), the increase in contractility that follows an extrasystole, is an interesting phenomenon that has been known for almost 100 years. The literature on this effect is reviewed. It is found that there is significant evidence that the phenomenon is independent of muscle loading and represents a distinct property of the myocardium. Examination of the literature pertaining to the cause of the effect suggests that calcium shifts within the sarcoplasmic reticulum are responsible, although there are some conflicts with this conclusion. Regarding the utility of PESP as a diagnostic test of latent viability of ischemic myocardium, the literature review reveals contradictions and conflicts with several methodological problems of the experiments. Finally, concerning the utility of continuous PESP (paired-pacing) to augment ventricular function in the failing ventricle, the studies again are inconclusive and methodologically suspect. Conditions for the proper analysis of the PESP response are reported, and suggestions for future studies are introduced.

Maximal postextrasystolic potentiation following multiple extrasystoles: a simple means of myocardial assessment

To obtain consistent, reproducible postextrasystolic potentiation (PESP), a single closely coupled extrasystole (ES) must be introduced using transvenous pacing. We hypothesized that multiple ES (spontaneous or catheter induced) produce maximal PESP at all coupling intervals (CI). Differences in PESP between single and double ES were assessed in dogs at varying CI by two different methods [systolic time intervals--PEP/LVET, and endocardial markers--ejection fraction (EF)]. Single ES produced variable decreases in PEP/LVET (-8.6 +/- 2.7% (SE) to -22.9 +/- 4.0%) depending on the CI duration. Double ES produced maximal decreases (-26.0 +/- 1.2%) at all CI. A similar relationship was noted for EF following single ES (8.6 +/- 2.7% to 43.0 +/- 4.0%) and double ES (42.9 +/- 1.3%). Double ES produced maximal PESP at all CI. This finding may allow simple myocardial assessment during routine left ventricular catheterization without simultaneous right ventricular catheterization.