Home  About us  Contact
 

Inappropriate Sinus Tachycardia (inappropriate + sinus_tachycardia)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Efficacy of Ivabradine in a Case of Inappropriate Sinus Tachycardia and Ventricular Dysfunction

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2010
ANTONELLA SETTE M.D.
Ivabradine in IST., We present a case of a 49-year-old man with inappropriate sinus tachycardia and ventricular dysfunction. The conventional treatment (ace-inhibitor and beta-blockers) was not well tolerated by the patient, so Ivabradine, a specific inhibitor of If current in the sinus node, was started. After 3 months of using this medication, we observed an improvement of ejection fraction and quality of life. (J Cardiovasc Electrophysiol, Vol. pp. 815-817, July 2010) [source]

Anatomy and Physiology of the Right Interganglionic Nerve: Implications for the Pathophysiology of Inappropriate Sinus Tachycardia

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2008
JING ZHOU M.D.
Objective: To simulate inappropriate sinus tachycardia (IST) in experimental animals. Background: We recently found that epinephrine injected into the anterior right ganglionated plexi (ARGP) adjacent to the sinoatrial (SA) node induced an arrhythmia simulating IST. Methods: In 19 anesthetized dogs, via a right thoracotomy, the course of the interganglionic nerve (IGN) from the right stellate ganglion along the superior vena cava to the heart was delineated. High-frequency stimulation (HFS; 0.1 msec duration, 20 Hz, 4.5,9.3 V) was applied to IGN at the junction of innominate vein and SVC. Results: HFS of the IGN significantly increased the sinus rate (SR) (baseline: 156 ± 19 beats/minutes [bpm], 4.5 V: 191 ± 28 bpm*, 8.0 V: 207 ± 23 bpm*, 9.3 V: 216 ± 18 bpm*; *P < 0.01 compared to baseline) without significant changes in A-H interval or blood pressure. P-wave morphology, ice mapping, and noncontact mapping indicated that this tachycardia was sinus tachycardia. In 8 of 19 dogs, injecting hexamethonium (5 mg), a ganglionic blocker, into the ARGP attenuated the response elicited by IGN stimulation (baseline: 160 ± 21 bpm, 4.5 V: 172 ± 32 bpm, 8.0 V: 197 ± 32 bpm*, 9.3 V: 206 ± 26 bpm*; *P < 0.05 compared to baseline). In 19 of 19 animals, after formaldehyde injection into the ARGP, SR acceleration induced by IGN stimulation was markedly attenuated (baseline: 149 ± 17 bpm, 4.5 V: 151 ± 21 bpm, 8.0 V: 155 ± 23 bpm, 9.3 V: 167 ± 24 bpm*; *P < 0.05 compared to baseline). Conclusions: HFS of the IGN caused a selective and significant acceleration of the SR. A significant portion of IGN traverses the ARGP or synapses with the autonomic ganglia in the ARGP before en route to the SA node. Dysautonomia involving the IGN and/or ARGP may play an important role in IST. [source]

Treatment of Inappropriate Sinus Tachycardia with Ivabradine in a Patient with Postural Orthostatic Tachycardia Syndrome and a Dual Chamber Pacemaker

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2009
SITARA KHAN M.R.C.P.
We present the case of a 44-year-old woman with postural orthostatic tachycardia syndrome (POTS) and a dual chamber pacemaker. The patient suffered from inappropriate sinus tachycardia that had been resistant to treatment with traditional rate-slowing medications. Ivabradine,the specific sinus node If current inhibitor,was used to successfully lower the heart rate. The patient had no evidence of POTS on repeat autonomic function testing, and there was a corresponding symptomatic benefit. We propose that this class of drugs, the use of which is established as antianginals, should be considered in patients with resistant inappropriate sinus tachycardia. [source]

Efficacy of Ivabradine in a Case of Inappropriate Sinus Tachycardia and Ventricular Dysfunction

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2010
ANTONELLA SETTE M.D.
Ivabradine in IST., We present a case of a 49-year-old man with inappropriate sinus tachycardia and ventricular dysfunction. The conventional treatment (ace-inhibitor and beta-blockers) was not well tolerated by the patient, so Ivabradine, a specific inhibitor of If current in the sinus node, was started. After 3 months of using this medication, we observed an improvement of ejection fraction and quality of life. (J Cardiovasc Electrophysiol, Vol. pp. 815-817, July 2010) [source]

Anatomy and Physiology of the Right Interganglionic Nerve: Implications for the Pathophysiology of Inappropriate Sinus Tachycardia

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2008
JING ZHOU M.D.
Objective: To simulate inappropriate sinus tachycardia (IST) in experimental animals. Background: We recently found that epinephrine injected into the anterior right ganglionated plexi (ARGP) adjacent to the sinoatrial (SA) node induced an arrhythmia simulating IST. Methods: In 19 anesthetized dogs, via a right thoracotomy, the course of the interganglionic nerve (IGN) from the right stellate ganglion along the superior vena cava to the heart was delineated. High-frequency stimulation (HFS; 0.1 msec duration, 20 Hz, 4.5,9.3 V) was applied to IGN at the junction of innominate vein and SVC. Results: HFS of the IGN significantly increased the sinus rate (SR) (baseline: 156 ± 19 beats/minutes [bpm], 4.5 V: 191 ± 28 bpm*, 8.0 V: 207 ± 23 bpm*, 9.3 V: 216 ± 18 bpm*; *P < 0.01 compared to baseline) without significant changes in A-H interval or blood pressure. P-wave morphology, ice mapping, and noncontact mapping indicated that this tachycardia was sinus tachycardia. In 8 of 19 dogs, injecting hexamethonium (5 mg), a ganglionic blocker, into the ARGP attenuated the response elicited by IGN stimulation (baseline: 160 ± 21 bpm, 4.5 V: 172 ± 32 bpm, 8.0 V: 197 ± 32 bpm*, 9.3 V: 206 ± 26 bpm*; *P < 0.05 compared to baseline). In 19 of 19 animals, after formaldehyde injection into the ARGP, SR acceleration induced by IGN stimulation was markedly attenuated (baseline: 149 ± 17 bpm, 4.5 V: 151 ± 21 bpm, 8.0 V: 155 ± 23 bpm, 9.3 V: 167 ± 24 bpm*; *P < 0.05 compared to baseline). Conclusions: HFS of the IGN caused a selective and significant acceleration of the SR. A significant portion of IGN traverses the ARGP or synapses with the autonomic ganglia in the ARGP before en route to the SA node. Dysautonomia involving the IGN and/or ARGP may play an important role in IST. [source]

Treatment of Inappropriate Sinus Tachycardia with Ivabradine in a Patient with Postural Orthostatic Tachycardia Syndrome and a Dual Chamber Pacemaker

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2009
SITARA KHAN M.R.C.P.
We present the case of a 44-year-old woman with postural orthostatic tachycardia syndrome (POTS) and a dual chamber pacemaker. The patient suffered from inappropriate sinus tachycardia that had been resistant to treatment with traditional rate-slowing medications. Ivabradine,the specific sinus node If current inhibitor,was used to successfully lower the heart rate. The patient had no evidence of POTS on repeat autonomic function testing, and there was a corresponding symptomatic benefit. We propose that this class of drugs, the use of which is established as antianginals, should be considered in patients with resistant inappropriate sinus tachycardia. [source]