Asirvatham, Samuel J.

AbstractIntroductionThe ablation of outflow tract premature ventricular contractions (PVCs) is generally safe and effective. In some patients, successful ablation sites may not correlate with the earliest activation. We sought to evaluate mechanistic and anatomic relevance of the region below the left sinus of Valsalva in variable morphology outflow tract ventricular arrhythmias.MethodsPVC cases where ablation was in the region inferior to the left sinus of Valsalva were identified. Procedural and demographic information and long‐term outcomes were obtained. Cadaver dissections to evaluate regional anatomy were done as well.ResultsA total of 51 cases were included (age 53 ± 10; 37 [73%] males). Ablation was done for high PVC burden (>20%; mean 27% ± 8%) and presence of symptoms (73%) or ejection fraction less than 50% (78%). QRS morphology included either R wave (8; 16%), Rs (9; 18%), or rS (67%) in lead I, no precordial transition (40; 78%), V2 transition, (7; 14%), or V3 transition (4; 8%). In 31 (61%), the site just below the left coronary cusp was the earliest site, while the remainder had another site earlier. Ablation was acutely successful in 50 of 51 (98%). After 3 months, success was noted in 48 of 51 (94%). In two patients, repeat ablation in the same region resulted in durable suppression.ConclusionThe cases presented emphasize the importance of a region centered below the left sinus of Valsalva, where multivariable morphology QRS may be successfully ablated. Consideration of mapping and ablation even when signals are late in this region may be warranted in previously failed ablation attempts or first‐line evaluation.

Background: The clinical utility of routine electrocardiographic monitoring following percutaneous coronary interventions (PCI) is not well studied. Methods: We prospectively evaluated the incidence, cost, and the clinical implications of actionable arrhythmia alarms on telemetry monitoring following PCI. One thousand three hundred fifty-eight PCI procedures (989 [72.8%] for acute coronary syndrome and 369 [27.2%] for stable angina) on patients admitted to nonintensive care unit were identified and divided into 2 groups; group 1, patients with actionable alarms (AA) and group 2, patients with non-AA. AA included (1) ≥3 s electrical pause or asystole; (2) high-grade Mobitz type II atrioventricular block or complete heart block; (3) ventricular fibrillation; (4) ventricular tachycardia (>15 beats); (5) atrial fibrillation with rapid ventricular response; (6) supraventricular tachycardia (>15 beats). Primary outcomes were 30-day all-cause mortality. Cost-savings analysis was performed. Results: Incidence of AA was 2.2% (37/1672). Time from end of procedure to AA was 5.5 (0.5, 24.5) hours. Patients with AA were older, presented with acute congestive heart failure or non–ST-segment–elevation myocardial infarction, and had multivessel or left main disease. The 30-day all-cause mortality was significantly higher in patients with AA (6.5% versus 0.3% in non-AA [ P <0.001]). Applying the standardized costing approach and tailored monitoring per the American Heart Association guidelines lead to potential cost savings of $622 480.95 for the entire population. Conclusions: AA following PCI were infrequent but were associated with increase in 30-day mortality. Following American Heart Association guidelines for monitoring after PCI can lead to substantial cost saving.

AbstractBackgroundThe accurate separation of undifferentiated wide complex tachycardias (WCTs) into ventricular tachycardia (VT) or supraventricular wide complex tachycardia (SWCT) using conventional, manually‐applied 12‐lead electrocardiogram (ECG) interpretation methods is difficult.PurposeWe sought to devise a new WCT differentiation method that operates solely on automated measurements routinely provided by computerized ECG interpretation software.MethodsIn a two‐part analysis, we developed and validated a logistic regression model (ie, VT Prediction Model) that utilizes routinely available computerized measurements derived from patients' paired WCT and baseline ECGs.ResultsThe derivation cohort consisted of 601 paired WCT (273 VT, 328 SWCT) and baseline ECGs from 421 patients. The VT Prediction Model, composed of WCT QRS duration (ms) (P < .0001), QRS duration change (ms) (P < .0001), QRS axis change (°) (P < .0001) and T axis change (°) (P < .0001), yielded effective VT and SWCT differentiation (area under the curve [AUC]: 0.924; confidence interval [CI]: 0.903‐0.944) for the derivation cohort. The validation cohort comprised 241 paired WCT (97 VT, 144 SWCT) and baseline ECGs from 177 patients. The VT Prediction Model's implementation on the validation cohort yielded effective WCT differentiation (AUC: 0.900; CI: 0.862‐0.939) with overall accuracy, sensitivity, and specificity of 85.0%, 80.4%, and 88.2%, respectively.ConclusionThe VT Prediction Model is an example of how readily available ECG measurements may be used to distinguish VT and SWCT effectively. Further study is needed to develop and refine newer WCT differentiation approaches that utilize computerized measurements provided by ECG interpretation software.

AbstractBackgroundLimited data are available regarding the demographics, disease associations, and long‐term prognosis of patients with inappropriate sinus tachycardia (IST).ObjectiveTo establish epidemiologic data for patients with IST, including symptom onset, comorbid disease, and long‐term outcomes.MethodsWe retrospectively reviewed all patients with an IST diagnosis at the Mayo Clinic (Rochester, MN) during a 20‐year period (1998‐2018). We extracted demographic data and clinical outcomes compared to an age and gender‐matched control group with atrioventricular nodal reentry tachycardia (AVNRT).ResultsWithin the study period, a total of 305 patients with IST were identified (mean follow‐up 3.5 years) with 92.1% female and mean age 33.2 ± 11.2 years. The most frequently identified circumstances triggering the condition included pregnancy (7.9%) and infectious illness (5.9%) while the most common comorbid conditions were depression (25.6%) and anxiety (24.6%). At diagnosis, the mean left ventricular ejection fraction (LVEF) was 62.3 ± 6.2%, with 77 patients having follow‐up echocardiographic data. No significant difference in LVEF was seen after a mean 4.9 ± 4.3‐year follow‐up (baseline LVEF 59.8 ± 10.7% vs subsequent 61.4 ± 8.1%; P = .2971). Two deaths occurred within the study period, with one related to myocardial infarction and the other noncardiac; compared to an age and gender‐matched AVNRT control group there was no excess mortality during the follow‐up period.ConclusionsIn our study cohort, IST predominately affects young females with structurally normal hearts and modest coexistent psychiatric disease. In most cases of IST, a major event occurring just before or at the time of diagnosis could not be identified, although nearly 8% of patients first noted symptoms during or shortly after pregnancy. In our cohort, there was no evidence of cardiomyopathy or mortality related to IST.

AbstractBackgroundInappropriate sinus tachycardia (IST) remains a clinical challenge because patients often are highly symptomatic and not responsive to medical therapy.ObjectiveTo study the safety and efficacy of stellate ganglion (SG) block and cardiac sympathetic denervation (CSD) in patients with IST.MethodsTwelve consecutive patients who had drug‐refractory IST (10 women) were studied. According to a prospectively initiated protocol, five patients underwent an electrophysiologic study before and after SG block (electrophysiology study group). The subsequent seven patients had ambulatory Holter monitoring before and after SG block (ambulatory group). All patients underwent SG block on the right side first, and then on the left side. Selected patients who had heart rate reduction ≥15 beats per minute (bpm) were recommended to consider CSD.ResultsThe mean (SD) baseline heart rate (HR) was 106 (21) bpm. The HR significantly decreased to 93 (20) bpm (P = .02) at 10 minutes after right SG block and remained significantly slower at 97(19) bpm at 60 minutes. Left SG block reduced HR from 99 (21) to 87(16) bpm (P = .02) at 60 minutes. SG block had no significant effect on blood pressure or HR response to isoproterenol or exercise (all P > .05). Five patients underwent right (n = 4) or bilateral (n = 1) CSD. The clinical outcomes were heterogeneous: one patient had complete and two had partial symptomatic relief, and two did not have improvement.ConclusionSG blockade modestly reduces resting HR but has no significant effect on HR during exercise. Permanent CSD may have a modest role in alleviating symptoms in selected patients with IST.