Diastolic Cardiac Pathology and Clinical Twin-Twin Transfusion Syndrome in Monochorionic/Diamniotic Twins

Abstract

OBJECTIVE: to identify differences in echocardiographic profiles of monochorionic/diamniotic pregnancies with early or mild twin-twin transfusion syndrome (TTTS), compared to monochorionic/diamniotic twins affected only by discordant growth or discordant fluid. STUDY DESIGN: retrospective evaluation of sonograms and echocardiograms of twin pregnancies referred for suspected TTTS. RESULTS: 112 monochorionic/diamniotic pairs were studied. 41 did not have/develop TTTS, 61 had Stage I/II TTTS. Ten developed TTTS after initially not meeting criteria. TTTS recipients had a higher rate of venous Doppler or tricuspid inflow abnormalities than purported "recipients" in non-TTTS pregnancies (86% vs. 37%, P<0.001). TTTS recipients had shorter tricuspid inflow duration/RR intervals than non-TTTS fetuses (32+/-6% versus 37+/-4%, P<0.001). Logistic regression and recursive partitioning identified shorter tricuspid inflow duration, longer isovolumic relaxation, and ductus venosus abnormality associated with TTTS. CONCLUSION: Diastolic pathology, specifically shorter tricuspid inflow duration, may be considered a hallmark of TTTS distinguishing these pregnancies from other monochorionic/diamniotic twin complications.

Figure 1

Normal and Abnormal Atrioventricular Valve (Tricuspid or Mitral) Inflow Doppler Signal. Upper panel shows a normal, biphasic inflow pattern with distinct “E” wave corresponding to early filling phase of diastole and separate “A” wave corresponding to atrial contraction. Lower panel shows a monophasic pattern with loss of early filling signal.

Figure 1

Normal and Abnormal Atrioventricular Valve (Tricuspid or Mitral) Inflow Doppler Signal. Upper panel shows a normal, biphasic inflow pattern with distinct “E” wave corresponding to early filling phase of diastole and separate “A” wave corresponding to atrial contraction. Lower panel shows a monophasic pattern with loss of early filling signal.

Figure 2

Doppler-derived measurements. Panel A shows a normal ductus venosus Doppler tracing, with peak “S” and “a” waves corresponding to systolic forward flow and atrial contraction, respectively. Panel B shows a normal inferior vena cava Doppler trace, with method for determining forward and reverse velocity-time integral (F VTI and R VTI respectively) corresponding to forward venous flow in systole and early diastole, and a normal small flow reversal with atrial contraction. Panel C shows a normal umbilical venous and arterial waveform, demonstrating a lack of significant notching in atrial systole. Panel D shows the Doppler signal obtained in the left ventricular outflow tract with simultaneous display of the inflow signal, with the method of determination of isovolumic relaxation time illustrated.

Figure 2

Doppler-derived measurements. Panel A shows a normal ductus venosus Doppler tracing, with peak “S” and “a” waves corresponding to systolic forward flow and atrial contraction, respectively. Panel B shows a normal inferior vena cava Doppler trace, with method for determining forward and reverse velocity-time integral (F VTI and R VTI respectively) corresponding to forward venous flow in systole and early diastole, and a normal small flow reversal with atrial contraction. Panel C shows a normal umbilical venous and arterial waveform, demonstrating a lack of significant notching in atrial systole. Panel D shows the Doppler signal obtained in the left ventricular outflow tract with simultaneous display of the inflow signal, with the method of determination of isovolumic relaxation time illustrated.

Figure 2

Doppler-derived measurements. Panel A shows a normal ductus venosus Doppler tracing, with peak “S” and “a” waves corresponding to systolic forward flow and atrial contraction, respectively. Panel B shows a normal inferior vena cava Doppler trace, with method for determining forward and reverse velocity-time integral (F VTI and R VTI respectively) corresponding to forward venous flow in systole and early diastole, and a normal small flow reversal with atrial contraction. Panel C shows a normal umbilical venous and arterial waveform, demonstrating a lack of significant notching in atrial systole. Panel D shows the Doppler signal obtained in the left ventricular outflow tract with simultaneous display of the inflow signal, with the method of determination of isovolumic relaxation time illustrated.

Figure 2

Doppler-derived measurements. Panel A shows a normal ductus venosus Doppler tracing, with peak “S” and “a” waves corresponding to systolic forward flow and atrial contraction, respectively. Panel B shows a normal inferior vena cava Doppler trace, with method for determining forward and reverse velocity-time integral (F VTI and R VTI respectively) corresponding to forward venous flow in systole and early diastole, and a normal small flow reversal with atrial contraction. Panel C shows a normal umbilical venous and arterial waveform, demonstrating a lack of significant notching in atrial systole. Panel D shows the Doppler signal obtained in the left ventricular outflow tract with simultaneous display of the inflow signal, with the method of determination of isovolumic relaxation time illustrated.

Figure 3

Measurement of tricuspid inflow duration (TV/RR). The measured inflow duration (*) is expressed as a percentage of the total cardiac cycle (R-R) duration.

Figure 4

Presence of Any Right Ventricular Diastolic Pathology on Initial Examination. Graph shows proportion of patients with (■) or without (□) any abnormal Doppler criteria (ductus venosus, inferior vena cava, umbilical venous, tricuspid inflow qualitative pattern) on initial examination in each ultrasound-defined group: Stage I, II = per Quintero staging; Progressed=initially negative, developed TTTS criteria after initial evaluation; non-TTTS= all other monochorionic/diamniotic pairs evaluated.

Figure 5

Box-and-whisker plots depicting tricuspid inflow duration as a percentage of cardiac cycle length (TVinflow) in the recipient twins studied in each ultrasound-defined group: Stage I, II = per Quintero staging; Progressed=initially negative, developed TTTS criteria after initial evaluation; non-TTTS= all other monochorionic/diamniotic pairs evaluated. Medians are represented by horizontal bars, boxes show upper and lower quartiles, whiskers 1.5 × interquartile range.

Figure 6

Tree structure (A) resulting from recursive partitioning analysis and graphic representation showing individual patient data (B). TVinflow, tricuspid inflow to cardiac cycle length ratio (TV/RR); DVSA, ductus venosus S:a ratio. Each node in the tree structure signifies a breakpoint in the data, with patients WITH disease breaking to the left on the diagram. In the accompanying graph, all points BELOW the bold line would be predicted to be in the TTTS group by the model.

Figure 6

Tree structure (A) resulting from recursive partitioning analysis and graphic representation showing individual patient data (B). TVinflow, tricuspid inflow to cardiac cycle length ratio (TV/RR); DVSA, ductus venosus S:a ratio. Each node in the tree structure signifies a breakpoint in the data, with patients WITH disease breaking to the left on the diagram. In the accompanying graph, all points BELOW the bold line would be predicted to be in the TTTS group by the model.