Chronotropic
|
WikiDoc Resources for Chronotropic |
|
Articles |
|---|
|
Most recent articles on Chronotropic Most cited articles on Chronotropic |
|
Media |
|
Powerpoint slides on Chronotropic |
|
Evidence Based Medicine |
|
Clinical Trials |
|
Ongoing Trials on Chronotropic at Clinical Trials.gov Clinical Trials on Chronotropic at Google
|
|
Guidelines / Policies / Govt |
|
US National Guidelines Clearinghouse on Chronotropic
|
|
Books |
|
News |
|
Commentary |
|
Definitions |
|
Patient Resources / Community |
|
Patient resources on Chronotropic Discussion groups on Chronotropic Patient Handouts on Chronotropic Directions to Hospitals Treating Chronotropic Risk calculators and risk factors for Chronotropic
|
|
Healthcare Provider Resources |
|
Causes & Risk Factors for Chronotropic |
|
Continuing Medical Education (CME) |
|
International |
|
|
|
Business |
|
Experimental / Informatics |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Chronotropic effects (from chrono-, meaning time) are those that change the heart rate.
Chronotropic drugs may change the heart rate by affecting the nerves controlling the heart, or by changing the rhythm produced by the sinoatrial node. Positive chronotropes increase heart rate; however, negative chronotropes decrease heart rate.
A dromotrope affects Atrioventricular node (AV node) conduction. A positive dromotrope increases AV nodal conduction, and a negative dromotrope decreases AV nodal conduction. A lusitrope is an agent that affects diastolic relaxation.
Many positive inotropes affect preload and afterload.
Negative Chronotropes
Chronotropic variables in systolic myocardial performance can be split left and right. Left sided systolic chronotropy can be appreciated as Aortic Valve open to close time. Right sided variables are represented by Pulmonary valve open to close time. Inverted as diastolic chronotropy, the variables are aortic valve close to open and pulmonic close to open time. Pharmaceutical manipulation of chronotropic properties was perhaps first appreciated by the introduction of digitalis.