Right diaphragmatic paralysis following endocardial cryothermal ablation of inappropriate sinus tachycardia.
Inappropriate sinus tachycardia (IST) is a rare disorder amenable to catheter ablation when refractory to medical therapy. Radiofrequency (RF) catheter modification/ablation of the sinus node (SN) is the usual approach, although it can be complicated by right phrenic nerve paralysis. We describe a patient with IST, who had symptomatic recurrences despite previous acutely successful RF SN modifications, including the use of electroanatomical mapping/navigation system. We decided to try transvenous cryothermal modification of the SN. We used 2 min applications at -85 degrees C at sites of the earliest atrial activation guided by activation mapping during isoprenaline infusion. Every application was preceded by high output stimulation to reveal phrenic nerve proximity. During the last application, heart rate slowly and persistently fell below 85 bpm despite isoprenaline infusion, but right diaphragmatic paralysis developed. At 6 months follow-up, the patient was asymptomatic and the diaphragmatic paralysis had partially resolved. This is the first report, we believe, of successful SN modification for IST by endocardial cryoablation, although this case also demonstrates the considerable risk of right phrenic nerve paralysis even with this ablation energy.
Vatasescu
Radu
R
Gottsegen György Hungarian Institute of Cardiology, Haller utca 29, H-1096 Budapest, Hungary.
Shalganov
Tchavdar
T
Kardos
Attila
A
Jalabadze
Khatuna
K
Paprika
Dora
D
Gyorgy
Margit
M
Szili-Torok
Tamas
T
D017115:Catheter Ablation / Q000379:methods*; D003452:Cryosurgery; D005260:Female; D006801:Humans; D008875:Middle Aged; D011183:Postoperative Complications; D012133:Respiratory Paralysis / Q000209:etiology*; D013616:Tachycardia, Sinus / Q000601:surgery*