Mark J. Holmberg

Impact of left atrial volume in prediction of outcome after cardiac resynchronization therapy

UNLABELLED Left atrial volume index (LAVI) as a predictor of mortality has not been well investigated in patients with cardiac resynchronization therapy (CRT). The purpose of this study is to evaluate the impact of LAVI in predicting mortality in CRT patients. METHODS We studied 100 consecutive patients who received CRT (male 73, age 69.9 ± 9.6 years). The follow-up duration of all echocardiographic measurements was 14.4 ± 10.5 months after CRT. LAVI was measured from apical views on two-dimensional echocardiography by bi-plane rule. A decrease of left ventricular end systolic volume ≥ 15% after CRT was defined as a positive response to CRT. RESULTS The mean LAVI at baseline was 59.9 ± 22.7 ml/m(2). LAVI in patients who died (78.2 ± 27.5 ml/m(2)) was significantly greater than those who survived (55.9 ± 19.5 ml/m(2), p<0.0001) during follow-up of 17 ± 10.6 months. The area under ROC curve (AUC) for LAVI predicting death was 0.77 (p=0.0001). The cutoff point for LAVI predicting death was LAVI>59.4 ml/m(2). LAVI>59.4 ml/m(2) was related to mortality by Cox proportional univariate regression [hazard ratio (HR)=5.15, 95% CI=1.48-17.93, p=0.01]. After adjustment for the variables with significant difference by univariate regression, LAVI>59.4 ml/m(2) was continuously related to mortality by multivariate regression (HR=4.56, 95% CI, 1.30-15.97, p=0.02). LAVI>59.4 ml/m(2) was associated with a near 5-fold increase in mortality during follow-up of 17 ± 10.6 months. CONCLUSION Patients who have LAVI>59.4 ml/m(2) continue to have increased mortality despite CRT.

Transesophageal echocardiography before cardioversion of recurrent atrial fibrillation: Does absence of previous atrial thrombi preclude the need of a repeat test?

BACKGROUND Atrial fibrillation (AF) is a recurrent problem that frequently requires repeat cardioversion. Transesophageal echocardiography (TEE) is indicated before cardioversion in patients who are underanticoagulated (warfarin therapy <3 weeks or international normalized ratio [INR] <2.0). It remains uncertain if TEE should be repeated in underanticoagulated patients who had no atrial thrombi detected by previous TEE. Methods and results From January 1996 to June 2001, 76 patients (43 men, 33 women; mean age, 68.8 +/- 10.4 years) who were underanticoagulated and had no atrial thrombi in previous TEE underwent repeat TEE before cardioversion of recurrent AF. The duration of recurrent AF at the time of the second TEE was 5.1 +/- 9.3 months (1 day to 4 years). The underlying diseases included coronary artery disease (n = 30), hypertension (n = 22), valvular heart diseases (n = 8), dilated cardiomyopathy (n = 4), hypertrophic cardiomyopathy (n = 2), and others (n = 10). Eight (10.5%) patients (2 men, 6 women; mean age, 68.6 +/- 6.6 years) were found to have intra-atrial thrombi on the second TEE. Of these 8 patients, 3 had coronary artery disease, 1 had hypertension, 2 had dilated cardiomyopathy, 1 had hypertrophic cardiomyopathy, and 1 had AF of unknown cause. The duration of recurrent AF in patients with and without thrombi was not significantly different (3.6 +/- 4.7 versus 5.3 +/- 9.7 months, P =.22). Of the 8 patients with intra-atrial thrombi on the second TEE, 5 had been taking warfarin for 3 to 4 weeks but had subtherapeutic INR and 3 were taking aspirin only. Compared with patients without intra-atrial thrombi, patients with intra-atrial thrombi had lower ejection fraction (32.5% +/- 18.1% versus 49.9% +/- 14.1%, P =.015), slower left atrial appendage empty velocity (0.22 +/- 0.08 versus 0.41 +/- 0.17 m/s, P <.01), and higher prevalence of spontaneous echo contrast (87.5%) than in patients without intra-atrial thrombi (19.1%, P <.05) but similar left atrial size (49.5 +/- 5.3 versus 47.3 +/- 7.1 mm, P =.15). Cardioversion was cancelled in all patients with atrial thrombi. CONCLUSIONS In underanticoagulated patients, repeat TEE is necessary before cardioversion of recurrent AF even if the previous TEE showed no atrial thrombi.

Thoracic aortic atheroma severity predicts high-risk coronary anatomy in patients undergoing transesophageal echocardiography.

Introduction We hypothesized a relationship between severity of thoracic aortic atheroma (AA) and prevalence of high-risk coronary anatomy (HRCA). Material and methods We investigated AA diagnosed by transesophageal echocardiography and HRCA diagnosed by coronary angiography in 187 patients. HRCA was defined as ≥ 50% stenosis of the left main coronary artery or significant 3-vessel coronary artery disease (≥ 70% narrowing). Results HRCA was present in 45 of 187 patients (24%). AA severity was grade I in 55 patients (29%), grade II in 71 patients (38%), grade III in 52 patients (28%), grade IV in 5 patients (3%), and grade V in 4 patients (2%). The area under receiver operating characteristic curve for AA grade predicting HRCA was 0.83 (p = 0.0001). The cut-off points of AA to predict HRCA was > II grade. The sensitivity and specificity of AA > grade II to predict HRCA were 76% and 81%, respectively. After adjustment for 10 variables with significant differences by univariate regression, AA > grade II was related to HRCA by multivariate regression (odds ratio = 7.5, p< 0.0001). During 41-month follow-up, 15 of 61 patients (25%) with AA >grade II and 10 of 126 patients (8%) with AA grade ≤ 2 died (p= 0.004). Survival by Kaplan-Meier plot in patients with AA > grade II was significantly decreased compared to patients with AA ≤ grade II (p= 0.002). Conclusions AA > grade II is associated with a 7.5 times increase in HRCA and with a significant reduction in all-cause mortality.

Effect of Mitral Regurgitation on Cerebrovascular Accidents in Patients with Atrial Fibrillation and Left Atrial Thrombus

The effect of mitral regurgitation (MR) on the incidence of new cerebrovascular accidents (CVA) and mortality in patients with atrial fibrillation (AF) and left atrial thrombus (LAT) is unknown.

Thromboembolism in Patients With Atrial Fibrillation With and Without Left Atrial Thrombus Documented by Transesophageal Echocardiography

The incidence of cerebrovascular events (CVEs) was investigated in 95 consecutive patients with atrial fibrillation (AF) with left atrial thrombus (LAT) diagnosed by transesophageal echocardiography (TEE) and in 131 age- and sex-matched AF patients without LAT. Compared with patients without LAT, patients with LAT had a larger left atrial diameter (49 versus 44 mm, P < 0.0001), a lower left ventricular ejection fraction (40% versus 50%, P < 0.0001), a higher prevalence of spontaneous echocardiographic contrast (88% versus 25%, P < 0.001), a reduced left atrial appendage emptying velocity (0.25 versus 0.41 cm/s, P < 0.0001), and less use of antiarrhythmic drugs (61% versus 76%, P = 0.03). Before TEE, the prevalence of prior CVE was higher in LAT patients (20%) compared with patients without LAT (8%) (P = 0.01). Fifty-four of 95 LAT patients (57%) and 81 of 131 non-LAT patients (62%) were on warfarin before TEE. The incidence of prior CVE in LAT patients without warfarin (32%) was higher than that in non-LAT patients without warfarin (10%) (P = 0.02). The mortality rate in LAT patients with an international normalized ratio (INR) ≥ 2.0 (42%) was higher than that in patients without LAT and an INR ≥ 2.0 (11%) (P < 0.001). Fifty-one of 95 LAT patients (54%) underwent repeat TEE before cardioversion (48 patients received warfarin therapy). The thrombus resolved in 40 of 51 patients (78%) after the first TEE. There was no significant difference in INR between the patients with persistent and resolved LAT. AF patients with persistent LAT had a higher incidence of CVE (45%) than the patients with resolved LAT (5%) (P = 0.003). We suggest that patients with LAT be treated with warfarin to maintain an INR between 2.5 and 3.5 rather than between 2.0 and 3.0 because they are at a high risk for new thromboembolism.

Real‐Time Three‐Dimensional Echocardiography in Diagnosis of Right Ventricular Pseudoaneurysm after Pacemaker Implantation

Right ventricular rupture is a critical cardiac complication associated with cardiac tamponade and death. Occasionally, the site of rupture may be contained by the parietal pericardium and thrombus, thus forming a pseudoaneurysm. Cases of traumatic pseudoaneurysm of the right ventricle have been reported. However, right ventricular pseudoaneurysm following pacemaker implantation has not been previously reported. This case demonstrates two right ventricular pseudoaneurysms following perforation of the right ventricular wall using real‐time three‐dimensional echocardiography (3DE) after pacemaker implantation although only one definite pseudoaneurysm was diagnosed by routine two‐dimensional echocardiography (2DE). We also found that color Doppler 3DE enhanced visualization of the connections between the right ventricle and the pseudoaneurysm. Color Doppler 3DE allowed us to peel away the myocardial tissue and rotate the image to study the jets from different angles. In summary, real‐time 3DE and color Doppler 3DE provided excellent visualization of the right ventricular pseudoaneurysm, flow between the ventricle and the pseudoaneurysm, and additional information to that obtained by 2DE.

Evaluation of left ventricular dyssynchrony using combined pulsed wave and tissue Doppler imaging

Introduction The combination of pulsed wave (PW) and tissue Doppler imaging (TDI) has been proposed as a new method to assess left ventricular (LV) mechanical dyssynchrony (LVMD), but results have not been validated. We investigated the correlation of a combination of PW and TDI with a positive response to cardiac resynchronization therapy (CRT). Material and methods We studied 108 consecutive patients who received CRT. Patients with atrial fibrillation were excluded. The time difference (TPW-TDI) between onset of QRS to the end of LV ejection by PW (TPW) and onset of QRS to the end of the systolic wave in LV basal segments with greatest delay by TDI (TTDI) was measured before CRT and during short-term and long-term follow-up. Results The TPW-TDI interval before CRT was 74 ±48 ms. Intra-observer variabilities for TPW and TTDI were 1.5 ±0.24% and 1 ±0.17%. Inter-observer variabilities for TPW and TTDI were 1 ±0.36% and 1 ±0.64%, respectively. TPW-TDI > 50 ms was defined as the cutoff value for diagnosis of LVMD by receiver operating curve (ROC) analysis. During follow-up of 15 ±11 months, the sensitivity and specificity of TPPW-TDI to predict a positive response to CRT were 98% and 82%, respectively. The area under the ROC curve was 0.92. There was a significant agreement between LVMD determined by TPW-TDI and the positive response to CRT (κ=0.80). Conclusions Left vertricular dyssynchrony detected by the method combining PW and TDI demonstrated a high reproducibility, sensitivity, specificity and agreement with a positive response to CRT.

Are the extent, location, and score of segmental wall motion abnormalities related to cardiac resynchronization therapy response?

Background: We hypothesized that segmental wall motion abnormalities (WMAs) are related to cardiac resynchronization therapy (CRT) response. Methods: We studied 108 patients who received CRT, 69 with ischemic and 39 with nonischemic heart disease. A wall motion score index (WMSI) was analyzed using a 17‐segment model and calculated by the total score/number of segments analyzed. A decrease of left ventricular end systolic volume ≥15% after CRT was defined as a positive response to CRT. Results: Of 108 patients, 1,054/1,836 segments (57%) had WMAs. The mean WMSI was 2.06 in patients with ischemic heart disease and 1.04 in patients with nonischemic heart disease (P < 0.0001). The area under the receiver operating characteristic curve for a WMSI predicting a positive response to CRT was 0.70 (P = 0.0001). The cutoff point was a WMSI ≤2 for prediction of a positive response to CRT. After adjustment for age, gender, and clinical features, the WMSI persistently related to CRT responders (P = 0.01). During 15‐month follow‐up, the percentage of CRT nonresponders in patients with a WMSI >2 was significantly higher (82%) compared to patients with a WMSI ≤2 (47%, P = 0.005) and nonischemic heart disease (36%, P < 0.001). In 59 patients with left ventricular mechanical dyssynchrony, the percentage of negative responders to CRT in patients with a WMSI >2, ≤2, and nonischemic heart disease were 53% (8 of 15), 16% (3 of 19) and 0% (0 of 25), respectively (P < 0.001). Conclusions: A large extent of WMAs and a WMSI >2 predicted a poorer CRT response. (ECHOCARDIOGRAPHY, Volume 26, November 2009)

Electrocardiographic Abnormalities of Takotsubo Cardiomyopathy in a Patient with Paced Ventricular Rhythm

Takotsubo cardiomyopathy (TCM) is a unique cardiomyopathy characterized by chest pain, ECG, and regional wall motion abnormalities closely mimicking acute myocardial infarction, in the absence of significant coronary artery disease. Classic ECG changes of TCM include ST elevation or T wave inversion. However, ECG abnormalities of TCM in patients with paced ventricular rhythms have not been well characterized. Herein, we report the case of an 85-year-old pacemaker dependant female who was diagnosed with TCM four weeks following the demise of her husband. Abnormal negative T wave concordance in precordial leads and QT interval prolongation were the only new ECG findings and these reverted back to baseline on followup.

Warfarin Therapy Initiated before Is More Beneficial Than after Transesophageal Echocardiography Detected Left Atrial Thrombus

Objective: Warfarin anticoagulation significantly reduces the risk of thromboembolism in patients with atrial fibrillation (AF). However, there are many patients with AF who begin anticoagulation only after left atrial thrombus (LAT) is detected by transesophageal echocardiography (TEE). The impact of anticoagulation in these patients has not been clearly described. The purpose of this study was to investigate the incidence of cerebrovascular accident (CVA) among AF patients who began warfarin before LAT was detected by TEE compared to those who began warfarin only after TEE demonstrated LAT and those did not receive warfarin at any point. Method: Of the 90 consecutive AF patients with LAT (male 48, female 42, age 71.5 ± 10.1 years), 49 began warfarin more than 3 weeks before TEE (Group I); 29 began warfarin after TEE (Group II); and 12 did not receive warfarin at all (Group III). Results: The incidence of CVA in Group I (14%, 7/49, prior CVA 5, new CVA after TEE 2) was significantly lower than Group II (45%, 13/29, prior CVA 10, new CVA after TEE 3, P = 0.006) and III (42%, 5/12, prior CVA 3, new CVA after TEE 2, P = 0.047). Patients with persistent LAT had significantly higher incidence (64% vs 23%, P = 0.024) of CVA and lower CVA free survival than those with resolved LAT. Conclusion: The incidence of CVA among AF patients, who began warfarin before LAT detection, is significantly lower than those who began warfarin after LAT detection as well as those who did not receive warfarin at all.