The incremental benefit of color tissue doppler in fetal arrhythmia assessment

BACKGROUND: Accurate fetal arrhythmia (FA) diagnosis is key for effective management. Currently, FA assessment relies on standard echocardiography-based techniques (M mode and spectral Doppler), which require adequate fetal position and cursor alignment to define temporal relationships of mechanical events. Few data exist on the application of color Doppler tissue imaging (c-DTI) in FA assessment. The aim of this study was to examine the feasibility and clinical applicability of c-DTI in FA assessment in comparison with standard techniques. METHODS: Pregnancies with diagnosed FA were prospectively recruited to undergo c-DTI following fetal echocardiography. Multiple-cycle four-chamber clips in any orientation were recorded (mean frame rate, 180 ± 16 frames/sec). With offline analysis, sample volumes were placed on atrial (A) and ventricular (V) free walls for simultaneous recordings. Atrial and ventricular rates, intervals (for atrial-ventricular conduction and tachyarrhythmia mechanism), and relationships were assessed to decipher FA mechanism. FA diagnosis by c-DTI, conventional echocardiographic techniques, and postnatal electrocardiography and/or Holter monitoring were compared. RESULTS: FA was assessed by c-DTI in 45 pregnancies at 15 to 39 weeks, including 16 with atrial and/or ventricular ectopic beats; 18 with supraventricular tachyarrhythmias, including ectopic atrial tachycardia in 11, atrioventricular reentrant tachycardia in four, atrial flutter in two, and intermittent atrial flutter and junctional ectopic rhythm in one; three with ventricular tachycardias; and eight with bradycardias or atrioventricular conduction pathology, including five with complete atrioventricular block (AVB), one with first-degree AVB evolving into complete AVB, one with second-degree AVB, and one with sinus bradycardia. After training, FA diagnosis by c-DTI could be made irrespective of fetal orientation within 10 to 15 min. FA diagnosis by c-DTI concurred with standard techniques in 41 cases (91%), with additional findings identified by c-DTI in 10. c-DTI led to new FA diagnoses in four cases (9%) not definable by standard techniques. FA diagnosis by c-DTI was confirmed in all 20 with persistent arrhythmias after birth, including three with new diagnoses defined by c-DTI. c-DTI was particularly helpful in deciphering SVT mechanism (long vs short ventricular-atrial interval) in all 18 cases, whereas standard techniques permitted definition in only half. CONCLUSIONS: c-DTI with offline analysis permits rapid and accurate definition of FA mechanism, providing new information in nearly one-third of affected pregnancies. AU

The Incremental Benefit of Color Tissue Doppler in Fetal Arrhythmia Assessment.

BACKGROUND: Accurate fetal arrhythmia (FA) diagnosis is key for effective management. Currently, FA assessment relies on standard echocardiography-based techniques (M mode and spectral Doppler), which require adequate fetal position and cursor alignment to define temporal relationships of mechanical events. Few data exist on the application of color Doppler tissue imaging (c-DTI) in FA assessment. The aim of this study was to examine the feasibility and clinical applicability of c-DTI in FA assessment in comparison with standard techniques. METHODS: Pregnancies with diagnosed FA were prospectively recruited to undergo c-DTI following fetal echocardiography. Multiple-cycle four-chamber clips in any orientation were recorded (mean frame rate, 180 ± 16 frames/sec). With offline analysis, sample volumes were placed on atrial (A) and ventricular (V) free walls for simultaneous recordings. Atrial and ventricular rates, intervals (for atrial-ventricular conduction and tachyarrhythmia mechanism), and relationships were assessed to decipher FA mechanism. FA diagnosis by c-DTI, conventional echocardiographic techniques, and postnatal electrocardiography and/or Holter monitoring were compared. RESULTS: FA was assessed by c-DTI in 45 pregnancies at 15 to 39 weeks, including 16 with atrial and/or ventricular ectopic beats; 18 with supraventricular tachyarrhythmias, including ectopic atrial tachycardia in 11, atrioventricular reentrant tachycardia in four, atrial flutter in two, and intermittent atrial flutter and junctional ectopic rhythm in one; three with ventricular tachycardias; and eight with bradycardias or atrioventricular conduction pathology, including five with complete atrioventricular block (AVB), one with first-degree AVB evolving into complete AVB, one with second-degree AVB, and one with sinus bradycardia. After training, FA diagnosis by c-DTI could be made irrespective of fetal orientation within 10 to 15 min. FA diagnosis by c-DTI concurred with standard techniques in 41 cases (91%), with additional findings identified by c-DTI in 10. c-DTI led to new FA diagnoses in four cases (9%) not definable by standard techniques. FA diagnosis by c-DTI was confirmed in all 20 with persistent arrhythmias after birth, including three with new diagnoses defined by c-DTI. c-DTI was particularly helpful in deciphering SVT mechanism (long vs short ventricular-atrial interval) in all 18 cases, whereas standard techniques permitted definition in only half. CONCLUSIONS: c-DTI with offline analysis permits rapid and accurate definition of FA mechanism, providing new information in nearly one-third of affected pregnancies.

The incremental benefit of color tissue doppler in fetal arrhythmia assessment

BACKGROUND: Accurate fetal arrhythmia diagnosis is key for effective management. Standard echo-based techniques (M-mode and spectral Doppler) require adequate fetal position and cursor alignment to define temporal relationships of mechanical events. Little data exists on the application of cTDI in fetal rhythm assessment. OBJECTIVE: We sought to determine the benefit of color tissue Doppler imaging (cTDI) in fetal arrhythmia assessment over conventional fetal echo techniques. METHODS: Pregnancies with a diagnosis of fetal arrhythmia were prospectively recruited to undergo cTDI following fetal echocardiography. Multiple cycle 4-chamber clips in any orientation were recorded (frame rates >180 fps). With offline analysis, sample-volumes were placed on atrial (A) and ventricular (V) free walls with simultaneous recordings. A and V rates, intervals and relationships were evaluated. RESULTS: Arrhythmias were assessed in 45 fetuses by cTDI at 15-39 weeks and included: 11 atrial and 5 ventricular ectopic beats; 18 supraventricular tachyarrhythmias (SVT) including ectopic atrial tachycardia in 11, AV re-entry SVT in 4, atrial flutter (AF) in 2, intermittent AF and junctional ectopic rhythm in 1; ventricular tachycardias in 3; 8 bradycardias or AV conduction pathology including complete AV block (AVB) in 5, 1 AVB evolving into complete AVB in 1, 2 AVB in 1, sinus bradycardia in 1. Arrhythmia diagnosis by cTDI could be made irrespective of orientation of the fetus, after training, within 10-15 minutes. cTDI findings concurred with the diagnosis by standard techniques in 95% of cases and added new findings in 29%. In 5%, cTDI provided a new diagnosis, confirmed postnatally. In cases with SVT, cTDI permitted assessment of A-V and V-A intervals elucidating arrhythmia mechanism in all, whereas standard techniques had failed to define mechanism in 45%. CONCLUSION: cTDI with offline analysis permits rapid and accurate definition of fetal arrhythmia mechanism, providing new information in a significant proportion of affected pregnancies. (AU)