BACKGROUND: Diminished cardiac vagal activity and higher heart rate predict a high mortality rate of chronic heart failure (CHF) after myocardial infarction. We investigated the effects of chronic electrical stimulation of the vagus nerve on cardiac remodeling and long-term survival in an animal model of CHF after large myocardial infarction. METHODS AND RESULTS: Two weeks after the ligation of the left coronary artery, surviving rats were randomized to vagal- and sham-stimulated groups. Using an implantable miniature radio-controlled electrical stimulator, we stimulated the right vagal nerve of CHF rats for 6 weeks. The intensity of electrical stimulation was adjusted for each rat, so that the heart rate was lowered by 20 to 30 beats per minute. The treated rats had significantly lower left ventricular end-diastolic pressure (17.1+/-5.9 versus 23.5+/-4.2 mm Hg, P<0.05) and higher maximum dp/dt of left ventricular pressure (4152+/-237 versus 2987+/-192 mm Hg/s, P<0.05) than the untreated rats. Improvement of cardiac pumping function was accompanied by a decrease in normalized biventricular weight (2.75+/-0.25 versus 3.14+/-0.22 g/kg, P<0.01). Although the 140-day survival of the untreated group was only half, vagal stimulation markedly improved the survival rate (86% versus 50%, P=0.008). Vagal stimulation therapy achieved a 73% reduction in a relative risk ratio of death. CONCLUSIONS: Vagal nerve stimulation markedly improved the long-term survival of CHF rats through the prevention of pumping failure and cardiac remodeling.
BACKGROUND: Diminished cardiac vagal activity and higher heart rate predict a high mortality rate of chronic heart failure (CHF) after myocardial infarction. We investigated the effects of chronic electrical stimulation of the vagus nerve on cardiac remodeling and long-term survival in an animal model of CHF after large myocardial infarction. METHODS AND RESULTS: Two weeks after the ligation of the left coronary artery, surviving rats were randomized to vagal- and sham-stimulated groups. Using an implantable miniature radio-controlled electrical stimulator, we stimulated the right vagal nerve of CHFrats for 6 weeks. The intensity of electrical stimulation was adjusted for each rat, so that the heart rate was lowered by 20 to 30 beats per minute. The treated rats had significantly lower left ventricular end-diastolic pressure (17.1+/-5.9 versus 23.5+/-4.2 mm Hg, P<0.05) and higher maximum dp/dt of left ventricular pressure (4152+/-237 versus 2987+/-192 mm Hg/s, P<0.05) than the untreated rats. Improvement of cardiac pumping function was accompanied by a decrease in normalized biventricular weight (2.75+/-0.25 versus 3.14+/-0.22 g/kg, P<0.01). Although the 140-day survival of the untreated group was only half, vagal stimulation markedly improved the survival rate (86% versus 50%, P=0.008). Vagal stimulation therapy achieved a 73% reduction in a relative risk ratio of death. CONCLUSIONS: Vagal nerve stimulation markedly improved the long-term survival of CHFrats through the prevention of pumping failure and cardiac remodeling.
Authors: Yuan Yuan; Jonathan L Hassel; Anisiia Doytchinova; David Adams; Keith C Wright; Chad Meshberger; Lan S Chen; Maria P Guerra; Changyu Shen; Shien-Fong Lin; Thomas H Everett; Vicenta Salanova; Peng-Sheng Chen Journal: Heart Rhythm Date: 2017-08-01 Impact factor: 6.343
Authors: Eric Beaumont; Elizabeth M Southerland; Jean C Hardwick; Gary L Wright; Shannon Ryan; Ying Li; Bruce H KenKnight; J Andrew Armour; Jeffrey L Ardell Journal: Am J Physiol Heart Circ Physiol Date: 2015-08-14 Impact factor: 4.733
Authors: Huiyin Tu; Jinxu Liu; Dongze Zhang; Hong Zheng; Kaushik P Patel; Kurtis G Cornish; Wei-Zhong Wang; Robert L Muelleman; Yu-Long Li Journal: Am J Physiol Cell Physiol Date: 2013-09-11 Impact factor: 4.249