CONTRAST ECHOCARDIOGRAPHY Detection of Thrombus Division of Cardiology Department of Internal Medicine Tae Kyung Yu

I. Detection of Thrombus Be aware of normal structure or non-pathologic conditions

Benign conditions misinterpreted as pathologies RA Chiari network Eustachian valve Crista terminalis Catheter/Pacemaker leads Lipomatous hypertrophy of IAS Pectinate muscle LA Suture line of cardiac transplant Calcified mitral annulus Coronary sinus Transverse sinus RV Moderator band Muscle bundles Trabeculations LV False chordae Papillary muscles LV trabeculation

I. Detection of Thrombus Consider the clinical settings for correct diagnosis Stasis of blood flow MS, A.fib, severe LV dysfunction, LV aneurysm Thrombus like lesions without stasis of blood flow Thrombus less likely

I. Detection of Thrombus Typically amormphous, echogenic structure Variable shape adherent to the endocardium Multiple , mobile and protrude into the cavity Generally involve the apex of the LV Presence of akinesia or dyskinesia

I. Detection of Thrombus Can be easily missed in routine echocardiography, if not suspected TTE Sensitivity 75~95% Always consider contrast echocardiography if not good apical visualization Sometimes even MRI or CT can miss apical thrombus, if not suspect

II. Contrast Echocardiography Microbubbles Agitated saline or contrast agent Gas-filled microbubbles Harmonic imaging Nonlinear oscillation Intermittent imaging Real-time myocardial perfusion imaging Microbubble에 높은 압력의 초음파를 투사하면 nonlinear oscillation하면서 주사된 것과 같은 주파수 이외에 기존의 주파수의 배수가 되는 harmonics를 발생하고 초음파에서 선택적으로 harmonics의 주파수에 해당하는 신호을 받아드린 것이 harmonic imaging 또한 더윽 증가된 세기의 초음파가 투사되면 microbubble은 파괴되고 내부의 gas가 노출되어 더 높은 harmonics를 만드므로 기포를 파괴시키는 것이 microbubble의 신호를 영상화하는데 가장 효과적인 방법으로 한 개의 pulse에 의해 미세비포가 파괴된 후 혈액의 관류에 따라 다시 미세기포가 조직내에 나타날때까지 일정 시간 기다렸다 투사하는 internittent imaging을 써야한다. 최근에는 continuous imaging으로 조영증가를 관찰하기위해 microbubble를 파괴시키지않는 비교적 작은 세기의 초음파로도 영상을 얻을 수 있는 새로운 기술이 발달되어 심근 조영과 함께 심근의 운동까지 동시에 관찰하는 real-time myocardial perfusion imaging이 이용되고 있다.

Clinical Applications A. Identify intracardiac and intrapulmonary shunts B. Augment doppler velocity signals C. Enhance the endocardial border D. Assess myocardial perfusion 3 Cardiac cavity 조영/ 1 심근 조영(most recently) 팔 -> SVC -> RA -> RV -> pul A 폐순환은 통과를 못함

A. Evaluation of Shunts Intracardiac and intrapulmonary shunts Agitated saline TEE of the right-left arterial shunt for patent foramen ovale (PFO) before (A) and after (B, C,) administration of contrast (Echovist) in patient Nº 35 of this series

B. Augmentation of the doppler velocity signal Right heart chambers by agitated saline TR velocity for estimation of the RVSP Left heart chambers by gas-filled microbubbles 폐모세혈관을 통과할 정도로 크기가 작고 혈액내에서 오래 존재할 수 있도록 용해가 어려운 gas를 shell 내부에 넣은 gas-filled microbubbles

C. Enhancement of the Definition of the Endocardial Border Gas-filled microbubbles evaluation of the ventricular walls is difficult because the patient's body habitus degraded the scan quality. (b) Following injection of a contrast agent, the left ventricular cavity becomes echogenic ("opacified") and this facilitates delineation of the endocardial border (arrowheads) so that the ejection fraction can be assessed.

D. Myocardial Perfusion Imaging Destruction and replenishment of microbubbles in real time no or decreased perfusion of myocardium -> not replenishment -> dark perfusion defect Visual assessment of myocardial contractility Combined with pharmacologic stress test (dobutamine or vasodilators)

Destruction replenishment imaging with real time ----- demonstrating absent perfusion to the anterior myocardial wall.

4CV at rest (left) and post stress (right) 4CV at rest (left) and post stress (right). Note there is no obvious difference in the shape of the cavity on the grey scale images. Importantly, the LVO images demonstrate a clear change in shape with the basal and mid lateral segments lagging, suggestive of LCx stenosis. In addition, the mid lateral segment has a perfusion defect which was not present at rest. Subtotal occlusion of the LCx was demonstrated at angiography.