Arzu Ilercil

Echocardiographic optimization of the atrioventricular and interventricular intervals during cardiac resynchronization.

An optimized atrioventricular (AV) interval can maximize the benefits of cardiac resynchronization therapy (CRT). If programmed poorly, it may curtail beneficial effects of CRT. AV optimization will not convert non-responder to responder, but may convert under-responder to improved status. There are many echocardiographic techniques for AV optimization but there is no universally accepted gold standard. The optimal AV delay varies with time, necessitating periodic re-evaluation. As the optimal AV delay may lengthen on exercise, a rate-adaptive AV delay should not be routinely programmed. Intra- and interatrial conduction delays may require AV junctional ablation when AV optimization is impossible in patients with a poor clinical response. Fusion with the spontaneous QRS complex may be acceptable on a trial basis to seek a better clinical response or with a short PR interval. Routine VV optimization is presently controversial but programming may prove beneficial in some patients with a suboptimal CRT response where no cause is found. It may partially compensate for less than optimal left ventricular (LV) lead position and may correct for heterogeneous ventricular activation including a prolonged LV latency interval and slow conduction (scarring) near the LV pacing site. VV timing is generally programmed using the aortic velocity-time integral, and long-term variations of the optimal value necessitate periodic re-evaluation.

Latency During Left Ventricular Pacing From the Lateral Cardiac Veins: A Cause of Ineffectual Biventricular Pacing

We report three patients with cardiomyopathy and pronounced stimulus to QRS latency during left ventricular (LV) pacing from an epicardial cardiac vein. Delayed LV activation during simultaneous biventricular pacing produced an electrocardiographic pattern dominated by right ventricular stimulation. Hemodynamic parameters improved immediately after advancing LV stimulation (in one patient) or pacing the LV only (in two patients) coupled with dramatic improvement of heart failure symptoms.

Site-Specific Differences in Latency Intervals during Biventricular Pacing: Impact on Paced QRS Morphology and Echo-Optimized V-V Interval

Objective:  To investigate differences in latency intervals during right ventricular (RV) pacing and left ventricular (LV) pacing from the (postero‐)lateral cardiac vein in cardiac resynchronization therapy (CRT) patients and their relationship to echo‐optimized interventricular (V‐V) intervals and paced QRS morphology.

Cross-sectional multiplane transesophageal echocardiographic measurements: comparison with standard transthoracic values obtained in the same setting.

Background: Several algorithms developed for cost‐effective use of transesophageal echocardiography (TEE) propose elimination of “screening” transthoracic echocardiographic (TTE) studies. Cross‐sectional measurements obtained by TTE (left atrial diameter [LAD], left ventricular internal dimensions in diastole and systole [LVIDd, LVIDs], septal and posterior wall thickness in diastole [VSTd, PWTd], LV end‐diastolic and end‐systolic volumes [LVEDV and LVESV], and LV ejection fraction [LVEF]) have not been standardized for TEE. Methods: Forty‐six patients (age 27 to 85 years, 60 ± 13 years, 25 [54%] women) underwent TEE and TTE studies. TTE was performed while the TEE probe was in place and the patient was still sedated. Standard TTE measurements were compared with corresponding TEE values obtained from mid‐esophageal and transgastric views. Results: Standard TTE measurements compared favorably with those obtained by TEE at the mid‐esophageal three‐chamber view for LAD (3.9 ± 0.6 cm vs 4.0 ± 0.7 cm, P = NS) and at the transgastric long‐axis view for LVIDd (4.6 ± 0.8 cm vs 4.7 ± 0.8 cm, P = NS), LVIDs (3.1 ± 0.9 cm vs 3.1 ± 0.9 cm, P = NS), and VSTd (0.95 ± 0.18 cm vs 0.98 ± 0.19 cm, P = NS). Biplane TTE and TEE measurements of LVEDV (106 ± 35 ml vs 112 ± 38 ml, P = NS), LVESV (37 ± 23 ml vs 37 ± 25 ml, P = NS), and LVEF (67 ± 14% vs 69 ± 14%, P = NS) also correlated closely. The negative predictive values of TEE measurements for excluding abnormal LAD, LVIDd, VSTd, PWTd, and LVEF as defined by TTE were 83%, 94%, 95%, 97%, and 97%, respectively. Conclusion: Cross‐sectional TEE measurements as obtained in this study are equivalent to standard TTE dimensions and provide reliable information that may facilitate interpretation of TEE studies in the absence of TTE information.

Mechanical esophageal deflection during ablation of atrial fibrillation.

To prevent esophageal damage during ablation of atrial fibrillation, we developed a technique to move the esophagus away from a desired ablation site too close to the esophagus. Under fluoroscopy, a transesophageal echocardiography probe was used to deflect the barium‐opacified esophagus from the ablation site. This technique was successfully employed in three patients where critical sites of the posterior left atrial wall were very close to the esophagus.

Association of noncompaction of left ventricular myocardium with Ebstein's anomaly.

A 41-year-old man was hospitalized for cellulitis related to left knee trauma. He was otherwise asymptomatic without significant past history apart from a heart murmur. Barring the left knee, physical examination was unremarkable except for a systolic murmur at the left sternal border. Complete blood count, electrolytes, and liver function tests were normal. Electrocardiogram showed sinus bradycardia at 55/min, normal P-wave morphology, in-

Cardiac Memory after Radiofrequency Ablation of Accessory Pathways: The Post-ablation T Wave Does not Forget the Pre-excited QRS

Introduction: Normalization of the pre-excited QRS following ablation is accompanied by repolarization changes but their directional relationship to changes in ventricular activation has not been well characterized.Methods: Accordingly, we measured QRS and T wave vectors and QRS-T angles from 12 lead ECG recordings immediately before and after accessory pathway (AP) radiofrequency ablation in 100 consecutive patients. Patients with bundle branch block, intraventricular conduction defect or intermittent pre-excitation were excluded, leaving a study group of 45 patients: 35 with pre-excitation and 10 with concealed APs.Results: With AP ablation, changes occurred in the QRS and T wave vectors and QRS-T angles that were essentially equal and opposite, so that the newly normalized QRS complex and QRS vector were accompanied by a T wave whose vector approximated that of the pre-ablation QRS vector. This tended to maintain a large QRS-T angle: 72° ± 50° before, and 54° ± 34° after QRS normalization (p = NS). A QRS-T angle >40° was found before and after ablation in 22/35 patients (63%) with baseline pre-excitation; but never in patients with a concealed AP (p = 0.001). The angle between the pre-excited QRS and the post-ablation T wave was 35° ± 37°, and ≤40° in 25/35 patients (71%). The change in T wave axis with QRS normalization correlated in magnitude with the QRS-T angle before ablation (r = 0.73, p < 0.0001). The change in QRS axis correlated with the QRS-T angle after ablation (r = 0.37, p < 0.03). Shorter AP effective refractory periods (ERPs) correlated with wider QRS-T angles after ablation (r = −0.39, p < 0.03). The ECG leads manifesting these changes depend on AP location.Conclusion: T-wave changes after ablation of APs (1) are dependent on anterograde AP conduction at baseline and are not observed with concealed APs; (2) correlate in magnitude directly with the change in QRS axis and inversely with the anterograde AP-ERP; (3) are related to AP location. With termination of pre-excitation secondary repolarization changes immediately disappear and the post ablation T wave axis approximates that of the pre-excited QRS. Recognition of this sequence may prevent unnecessary clinical interventions.

Clinical significance of fossa ovalis membrane aneurysm in adults with cardioembolic cerebral ischemia

Fossa ovalis membrane aneurysm was diagnosed by transesophageal echocardiography in 45 of 134 consecutive patients (34%) with embolic cerebrovascular ischemic events. A potential cardiovascular source of embolism, other than the fossa ovalis membrane aneurysm, was found in 91% of these patients (41 of 45).

Esophageal Contour Changes during Cryoablation of Atrial Fibrillation

Background: We have observed contour changes of the barium‐filled esophagus during atrial fibrillation (AF) ablation with cryo‐energy delivered in direct proximity to the esophagus.

Effect of early administration of atropine on paradoxic sinus deceleration during dobutamine stress echocardiography

Dobutamine stress echocardiography (DSE) is a well-established, safe, and reliable technique for diagnosis of coronary artery disease. The generally accepted protocol for DSE involves infusion of increasing doses of dobutamine from 5 to 40 g/kg/min at 3-minute intervals. In about 1/3 of patients, however, target heart rate cannot be achieved by the administration of dobutamine alone. Failure to achieve an adequate heart rate during DSE is attributed to the use of -adrenergic blocking agents, chronotropic incompetence, or paradoxic sinus deceleration (PSD). PSD is characterized by an initial increase followed by a significant decrease in heart rate during incremental doses of dobutamine. This is believed to result from activation of the cardioinhibitory reflex (Bezold-Jarisch reflex) through left ventricular sensory receptors. Although suggested by some, it is unclear whether left ventricular inferoposterior wall ischemia is the trigger for PSD. In the present study, we sought to identify the characteristics of patients with PSD during DSE and to determine whether early administration of atropine could prevent its development. • • • The study population consisted of 114 consecutive patients (age 36 to 91 years [66 12]; 66 women [58%]) with suspected coronary artery disease who were referred for DSE between March and June 2000. Patients were prospectively randomized into 2 protocols. Group A (n 55) underwent standard DSE protocol, consisting of incremental doses of dobutamine from 5 to 40 g/kg/min at 3-minute intervals, and if needed, up to 1 mg of atropine (0.25 mg doses at 2-minute intervals) at the completion of the 40 g/kg/min dose of dobutamine. A 3-minute infusion of dobutamine at 50 g/kg/min was given if necessary at peak (n 2). Patients in group B (n 59) underwent the same protocol except for administration of atropine at completion of the 10 g/kg/min dose of dobutamine with the aim to increase heart rate by 25% before advancing to the next dose of dobutamine. Atropine was not administered if the patient had a specific contraindication. End points for DSE termination were: (1) attainment of target heart rate, (2) completion of stress protocol, (3) echocardiographic evidence of ischemia, or (4) development of significant arrhythmia, hypertension, hypotension, or intolerable symptoms. A standard echocardiographic image acquisition protocol was used and heart rate was recorded from 12-lead electrocardiograms performed at 1-minute intervals. DSE was considered positive for ischemia if any worsening in left ventricular wall motion developed during the test except for a change from akinesia to dyskinesia. PSD was defined as a reduction in heart rate of 5 beats/min lasting for 3 minutes at dobutamine infusion rates of 10 g/kg/min. Data are presented as mean SD and numbers and percentages. Differences between continuous variables were assessed with the unpaired Student’s t test. Chi-square or Fisher’s exact test compared proportions. No statistically significant differences were noted between the 2 groups with regard to age, sex, baseline heart rate, blood pressure, and left ventricular ejection fraction, as well as risk factors for coronary artery disease (Table 1). Similarly, the number of patients who were on -adrenergic blocking agents was not significantly different in the 2 groups (28 [52%] vs 35 [59%], p NS) (Table 1). An equal proportion of the patients in the 2 groups (73%) reached target heart rate ( 85% predicted maximum heart rate for age). In addition, DSE was terminated in 7 patients (13%) in group A and 6 patients (10%) in group B due to myocardial ischemia (p NS). Coronary angiography was performed within 1 month of DSE in 9 of these 13 patients (5 in group A and 4 in group B) and showed significant coronary artery disease ( 50% luminal narrowing in 1 major epicardial coronary artery) in all patients. Safety considerations were the reasons for termination of DSE in 6 patients (11%) in group A and 2 patients (3%) in group B (p NS). The remaining 2 patients (3%) in group A and 8 patients (14%) in group B did not reach target heart rate despite maximal doses of dobutamine and atropine (if not contraindicated) (p NS). Five of the 8 patients in group B who did not reach target heart rate were taking -adrenergic blocking agents, From the Department of Medicine, Division of Cardiology, Albert Einstein College of Medicine, Bronx, New York. Dr. Shirani’s address is: Jack D. Weiler Hospital of the Albert Einstein College of Medicine, Division of Cardiology, 1825 Eastchester Road, Bronx, New York 10461-2373. E-mail: jshirani@montefiore.org. Manuscript received August 6, 2001; revised manuscript received and accepted October 31, 2001.