Reentry Tachycardia in Children: Adenosine Can Make It Worse.

OBJECTIVES: We report on a rare but severe complication of adenosine use in a child with reentry tachycardia. METHODS AND RESULTS: Treatment with adenosine, which is the standard medical therapy of atrioventricular reentry tachycardia, led to the development of an irregular wide complex tachycardia, caused by rapid ventricular response to atrial fibrillation. The girl was finally stabilized with electrical cardioversion. We analyze the pathomechanism and discuss possible treatment options. CONCLUSIONS: Atrial fibrillation, as well as its conduction to the ventricles, can be caused by adenosine. Rapid ventricular response in children with Wolff-Parkinson-White syndrome is more frequent than previously believed. A patient history of atrial fibrillation is a contraindication for cardioversion with adenosine and needs to be assessed in children with reentry tachycardia. High-risk patients may potentially profit from prophylactic comedication with antiarrhythmic agents, such as flecainide, ibutilide, or vernakalant, before adenosine administration.

Image quality influences the assessment of left ventricular function: an intraoperative comparison of five 2-dimensional echocardiographic methods with real-time 3-dimensional echocardiography as a reference.

OBJECTIVES: Transesophageal echocardiography has become a standard tool for evaluating left ventricular function during cardiac surgery. However, the image quality varies widely between patients and examinations. The aim of this study was to investigate the influence of the image quality on 5 commonly used 2-dimensional methods. METHODS: Transesophageal real-time 3-dimensional echocardiography (3DE) served as a reference. Left ventricular function was evaluated in 63 patients with sufficient real-time 3DE image quality. The image quality was rated using the ratio of the visualized border divided by the total endocardial border. These ratings were used to generate groups of poor (0%-40%), fair (41%-70%), and good (71%-100%) image quality. The ejection fraction (EF), end-diastolic volume, and end-systolic volume were analyzed by the Simpson method of disks (biplane and monoplane), eyeball method, Teichholz method, and speckle-tracking method. Furthermore, the fractional area change was determined. Each correlation with real-time 3DE was evaluated. RESULTS: Correlations of the EF and volumes, respectively, as determined by long-axis view methods increased with improving image quality: the Simpson biplane method was found to be the most accurate method, with good image quality for the EF (r = 0.946) and volumes (end-diastolic volume, r = 0.962; end-systolic volume, r = 0.989). Correlations of the EF and fractional area change by short-axis view methods decreased with improving image quality, with the Teichholz EF found to be most accurate with poor (r = 0.928) in contrast to good (r = 0.699) image quality. CONCLUSIONS: With good image quality, the Simpson biplane method is the most accurate 2-dimensional method for assessing the left ventricular EF. Short-axis view methods, especially the Teichholz method yield better correlations with poor image quality. The eyeball method was unaffected by image quality.

Assessment of left ventricular size and function during cardiac surgery. An intraoperative evaluation of six two-dimensional echocardiographic methods with real time three-dimensional echocardiography as a reference.

Transesophageal echocardiography is recommended to monitor left ventricular (LV) size and function in various operations. Generally, two-dimensional (2D) methods are applied intraoperatively. The aim of this study was to compare the accuracy and feasibility of 6 commonly used 2D methods to assess LV function during surgery. LV function in 120 consecutive patients was evaluated. Real time three-dimensional transesophageal echocardiograpy (3DTEE) served as reference. End-diastolic and end-systolic volumes and ejection fraction (EF) were analyzed with Simpson's method of discs (monoplane [MP] and biplane [BP]), eyeball method, Teichholz' method, and speckle tracking (ST) methods. Furthermore, fractional area change (FAC) and peak systolic pressure rise (dP/dt) were determined. Each 2D method was evaluated regarding correlation and agreement with 3DE, intra- and interobserver variability and the time required for evaluation. Simpson BP showed the strongest correlation and best agreement with 3DE for EF (limits of agreement 3.7 ± 11.6%) and volumes. Simpson MP showed similar agreement with 3DE compared to ST (2.8 ± 14.5% vs. 2.0 ± 15.3% and 3.8 ± 14.4% vs. 1.9 ± 15.6%, respectively). Both the eyeball method and Teichholz' method showed wide limits of agreement (-1.5 ± 18.2% and 5.2 ± 22.1%, respectively). DP/dt did not correlate with 3DE. FAC and ST FAC showed similar agreement. Application of 3DE (429 ± 108 seconds) took the longest time, and the eyeball method took the shortest time (8 ± 5 seconds) for analysis. Simpson BP is the most accurate intraoperative 2D method to evaluate LV function, followed by long-axis MP evaluations. Short-axis views were less accurate but may be suited for monitoring. We do not recommend using dP/dt.

Comparison of intraoperative three-dimensional Doppler color flow mapping to assess mitral regurgitation.

BACKGROUND: Three-dimensional (3D) transesophageal echocardiography (TEE) enables the determination of the vena contracta area (VCA), which is an approved parameter to quantify mitral regurgitation (MR). The aim of this study was to determine the VCA in the operative setting and to compare it to alternative 3D and standard 2D methods, with respect to different etiologies of MR. METHODS: MR in 56 consecutive patients undergoing cardiac surgery was evaluated using 2D and 3D TEE. VCA, vena contracta (VC), and effective regurgitation orifice area (EROA) by 3D and 2D flow convergence methods were determined. The correlations among the methods and the determined areas were evaluated. RESULTS: EROA determination using 3D flow convergence areas correlated strongly with VCA (r = 0.653), however the resulting areas were considerably smaller. VC measurements in the 3D data set correlated slightly less (r = 0.629). EROA, which was determined using 2D flow convergence areas, showed the strongest correlation among the 2D methods (r = 0.406). 2D VC measurements showed weak to no correlation with VCA. Although a correlation was detected when using the biplane method or the midesophageal long-axis view to measure VC, statistical significance was only reached in functional MR and MR due to simple prolapse. CONCLUSIONS: Intraoperative 3D methods to determine MR were feasible and showed improved correlation with VCA compared to 2D measurements. The agreement of 2D methods with VCA declined from functional MR to MR due to prolapse. We recommend the utilization of 3D color Doppler for intraoperative evaluation of MR, especially in patients with complex mitral valve prolapses.

Cardiac and hemodynamic consequences during capnoperitoneum and steep Trendelenburg positioning: lessons learned from robot-assisted laparoscopic prostatectomy.

STUDY OBJECTIVE: To determine and interpret the changes in preload, afterload, and cardiac function in the different phases of robot-assisted laparoscopic prostatectomy. DESIGN: Prospective, observational monocenter study. SETTING: Operating room at a university hospital. PATIENTS: 31 consecutive, ASA physical status 1, 2, and 3 patients. INTERVENTIONS: Observations were made at 5 distinct time points: baseline after induction of anesthesia, after initiation of capnoperitoneum, immediately after a 45° head-down tilt, 15 minutes after the 45° head-down tilt was established, after the release of the capnoperitoneum, and 5 minutes after the patient was returned to a horizontal position (end). MEASUREMENTS: Transpulmonary thermodilution and pulse contour analysis were used to record hemodynamic changes in preload, afterload, and cardiac function. MAIN RESULTS: While central venous pressure increased threefold from baseline, none of the other preload parameters showed excessive fluid overload or demand. There was no significant change in cardiac contractility over time. Afterload increased significantly during the capnoperitoneum and significantly decreased compared with baseline after the release of abdominal pressure at the end of the procedure. Heart rate and cardiac index increased significantly during robot-assisted laparoscopic prostatectomy. CONCLUSIONS: Selective arterial vasodilation at the time of capnoperitoneum may normalize afterload and myocardial oxygen demand.

Left ventricular outflow tract: intraoperative measurement and changes caused by mitral valve surgery.

BACKGROUND: The impact of mitral valve surgery on left ventricular outflow tract (LVOT) dimensions is unclear. Real-time three-dimensional transesophageal echocardiography permits excellent visualization of the LVOT and might improve standard two-dimensional measurements. In this study, LVOT area and shape were assessed before and after mitral valve surgery. METHODS: Thirty-five patients undergoing mitral valve repair or replacement were retrospectively included in the study and compared with 15 patients undergoing coronary artery bypass grafting. LVOT area was measured by planimetry. Maximum possible methodologic errors by assuming a circular LVOT and an eccentricity index were calculated. LVOT diameter in a midesophageal long-axis view served to calculate the error for the circular LVOT determined in common intraoperative practice. RESULTS: Common intraoperative two-dimensional measurements underestimated actual LVOT area by 21%. Mitral valve surgery led to a significant reduction of LVOT area by 7%. Although LVOT height remained unchanged, width decreased from 2.72 to 2.53 cm (-7%), resulting in a more circular shape of the LVOT. This effect was more pronounced the smaller the size of the implanted annuloplasty ring or prosthesis. Coronary artery bypass grafting did not affect the LVOT. Left ventricular ejection fraction was significantly correlated with LVOT eccentricity. Impaired ventricular function and higher end-systolic volumes were associated with a rounder shape. CONCLUSIONS: The eccentric LVOT shape leads to a distinct underestimation of its area with two-dimensional measurements. LVOT eccentricity is less distinct in patients with low ejection fractions and higher end-systolic volumes. LVOT width is decreased through annuloplasty rings and prostheses, and the smaller the implanted device, the more profound the reduction.