Revista Română de Anatomie funcţională şi clinică, macro- şi microscopică şi de Antropologie Vol. XIV Nr. 2 2015 UPDATES ANATOMICAL IMAGING USING 3D ECHOCARDIOGRAPHY IN PATIENTS WITH MECHANICAL COMPLICATIONS POST MYOCARDIAL INFARCTION Andreea Cuculici, O. Chioncel, Cristina Ceck, E. Apetrei, Carmen Ginghina 1. Emergency Hospital of cardiovascular diseases Prof. Dr. C.C. Iliescu Bucharest ANATOMICAL IMAGING USING 3D ECHOCARDIOGRAPHY IN PATIENTS WITH ME- CHANICAL COMPLICATIONS POST MYOCARDIAL INFARCTION (Abstract): Introduction: Real-time three-dimensional echocardiography (RT3DE) permits rapid and complete acquisition of cardiac structures winning great clinical importance because a precise quantifications in viewing cardiac morphology and anatomical relations. Purpose: Highlighting the role and utility of RT3DE in the evaluation of anatomical mechanical complications after acute myocardial infarction. Methods: were studied 9 patients who presented with mechanical complications after myocardial infarction at Emergency Institute for Cardiovascular Diseases Prof. Dr. C.C. Iliescu Bucharest in October 2014 - February 2015 period. All patients were evaluated according to existing medical protocol (ECG, echocardiography, coronary angiography). Results: The mean age was 57 ± 6 years and 5 patients were male. Mechanical complications were defined as ventricular septal defect (5 patients), left ventricular free wall rupture (2 patients) and papillary muscle rupture (2 patients). 6 patients associate LV aneurysm (4 apicoseptal and two posterior). Anatomical localization of the solution of continuity and neighborhood relations were identified by RT3DE in all patients. In addition to two-dimensional echocardiography, RT3DE allowed calculating the area of continuity solution, identification of exact mechanism of mitral regurgitation and quantification of ventricular function. Conclusion(s): RT3DE provides important data of continuity solutions relations with neighboring anatomical structures, can measure the continuity solutions area and valvular lesions, favoring the surgeon in choosing the optimal surgical technique. RT3DE allows simultaneous analysis of systolic function and contractility disorders without making geometric assumptions like two-dimensional echocardiography. Key words: RT3DE, MECHANICAL COMPLICATIONS The major mechanical complications after acute myocardial infarction (AMI) include rupture of the left ventricular free wall, papillary muscle rupture, and ventricular septal rupture. Primary percutaneous coronary intervention has significantly reduced major mechanical complications since its introduction as a treatment strategy in AMI. Echocardiography with colorflow Doppler is the investigation of choice in establishing the positive and differential diagnosis of the aforementioned conditions. Papillary Muscle Rupture: Rupture of a papillary muscle after AMI is a surgical emergency with high mortality, nearly twice as much as an acute ventricular septal defect (VSD). Clinical presentation is usually with acute pulmonary oedema, hypotension and a new systolic murmur. Rupture of the posterior-medial papillary muscle with associated posterior leaflet flail is more commonly encountered and is usually secondary to an inferior MI. This is because the antero-lateral papillary muscle is frequently supplied by both left anterior descending and circumflex arteries. The posteromedial papillary muscle is usually supplied only by the posterior descending artery and is therefore prone to ischemia and rupture. Characteristic echo features which suggest papillary muscle rupture are: posterior mitral leaflet flail and severe mitral regurgitation; a mobile mass attached to the chords and mitral leaflet which exhibits systolic prolapse into the 211
Andreea Cuculici et al. Fig. 1. 2D. Echo-papillary muscle rupture Fig. 2. 3D Echo-papillary muscle rupture Fig. 3. Anatomical section of papillary muscle left atrium and moves back into the left ventricle during diastole (the ruptured papillary muscle); an abrupt cut off of the papillary muscle at the site of the rupture or just the erratic motion of the papillary muscle within the left ventricle. Sometimes a ruptured papillary muscle cannot be visualized using transthoracic echo, despite demonstrating mitral leaflet flail and severe mitral regurgitation. In these cases, trans esophageal echo is required and it is particularly useful when the detached papillary muscle (PM) is not seen to enter the left atrium by transthoracic echo but rupture is suspected from indirect features, such as the appearance of the valve and its abnormal motion. 3D Echo was useful in establishing the saddle-shaped, non-planar shape of the mitral annulus and helped explore the complex geometric relationship between the PM and leaflet position relative to the mitral annulus and LV outflow tract and most recently, made it possible to measure mitral leaflet size in the beating heart. As a consequence, non-planar mitral annuloplasty rings have been developed, and we could have a detailed understanding of the mechanisms underlying ischemic/functional mitral regurgitation. A 78-year-old female with cardiovascular risk factors (type 2 diabetes mellitus, hypertension, obesity) with a history of inferior ST-elevation acute myocardial infarction 2 weeks ago (treated conservatively) presented to our department for hemodynamic instability and pulmonary edema, associated with early recurrence of chest pain previous post myocardial infarction.physical examination on admission showed tachycardia (100 bpm), with a BP of 100/60 mmhg, a grade III of VI holosystolic murmur at the apex, reduced breath sounds and crackles bilaterally. Transthoracic echocardiography demonstrated akinesia of the postero-lateral wall with an estimated left ventricular ejection fraction of 50%, normal dimensions of both atria, moderate secondary tricuspid regurgitation, severe pulmonary hypertension (estimated systolic pressure of 60 mmhg) and normally functioning right ventricle. Mitral valve evaluation showed restriction of the posterior leaflet and ample movement of the anterior leaflet, with severe, eccentric mitral regurgitation. Real time 3D transoesophageal echography confirmed partial rupture of the posterior PM, with severe mitral insufficiency (Figure 1,2,3). Myocardial Rupture: Patients with free wall rupture typically present with hypotension and with pericardial chest pain, and in certain cases with nausea. The risk is highest around three to seven days post MI, when the necrotic myocardial tissue is most fragile and most prone to rupture. Left ventricular free wall rupture is the most common mechanical complication and is frequently fatal because the resulting haemopericardium is followed by cardiac tamponade. 212
Anatomical Imaging Using 3D Echocardiography in Patients with Mechanical Complications Fig. 4. 2D Echo-myocardial free wall rupture Rarely ventricular rupture can present subacutely, when the myocardial tear and accompanied bleeding is partially contained. Echo is pivotal in establishing the diagnosis, and free wall rupture should be considered in any patient with acute collapse post MI. The detection of pericardial fluid, even if the actual site of myocardial rupture cannot be visualized, is highly specific for this condition, which is more common in elderly patients and women, possibly due to thinner myocardial walls. The most common finding on echo is a localized pericardial effusion overlying a region of akinesia. The rupture site is usually difficult to be visualized on 2D echo, but may be suspected using color Doppler, which shows flow into the pericardium. The use of real-time 3D echo in assessing the complex geometry of ventricular rupture site has been demonstrated by the potential of this examination in localizing the location of LV rupture, describing the orifice s geometry, and proving the complex intracardiac flow. The wall rupture is typically localized in the anterior or lateral walls of the left ventricle, in the region supplied by the terminal branches of the left anterior descending artery, at the interface between infarcted tissue and normal myocardium. It usually complicates a STEMI since it involves the whole myocardial wall. A 68 year-old patient, with cardiovascular risk factors smoker, hypertensive, with dyslipidemia, previously diagnosed with significant coronary lesions (90% stenosis on LA- DIII, PCI with stenting on RCII for a 80% stenosis on april 2007), presented in our department on the 6 th day after an anterolateral myocardial infarction with syncope, intense anginal Fig. 5. 3D Echo-myocardial free wall rupture Fig. 6. Anatomical section myocardial free wall rupture pain and dyspnea. Physical examination revealed tachycardia (96 bmp), BP=100/50 mmhg, SaO2=85%, a holosystolic murmur on the left sternal border, bilateral crackles and systemic congestion. 3D echocardiography demonstrated a spiroid LV free wall rupture (from the endocardium to the epicardium) Figure 4,5,6. Ventricular Septal Rupture: Ventricular septal defect (VSD) typically occurs after an anterior or right ventricular infarct, usually following an extensive infarction. A VSD is more common in the elderly and, as in free wall rupture, is a complication of a transmural myocardial infarction. When a patient develops a new pan systolic murmur with hypotension in the first week post MI, the differential diagnosis is either acute mitral regurgitation or a ruptured ventricular septum resulting in a VSD. A VSD occurs if the infarction involves the ventricular septum and the soft, necrotic myocardium ruptures resulting in a left-to-right shunt. As a result, VSD 213
Andreea Cuculici et al. Fig. 8. 3D Echo-Posterior VSD post AMI Fig. 7. 3D Echo-Inferior VSD post AMI Fig. 9. 3D Echo-Apical VSD post AMI is followed by haemodynamic deterioration, with hypotension, heart failure and cardiogenic shock. Simple VSD is defined by a direct communication through the septum, with the continuity between left and right ventricles localized at the same level. Complex ruptures are those which track along the septum, often accompanied by thrombus, before rupturing into the right ventricle. The communication is irregular and runs a serpiginous course through the necrotic myocardium of the septum With anterior infarcts, the VSD is invariably located at the apex and is usually simple, whereas the VSD of an inferior MI is positioned in the basal infero-posterior septum and is often complex. These VSDs carry a much worse prognosis. Unlike free wall rupture, VSD is associated with conduction disturbances, including complete heart block, reflecting the course of the cardiac conduction system. Echo is used to define the site, size and hemodynamic consequence of the VSD. An important prognostic indicator post VSD is the size and function of the right ventricle and a precise evaluation of the right ventricular function is paramount in making a surgical decision. Biventricular failure usually develops within hours or days and the mortality from acute VSD is high. When a VSD is suspected, a systematic echo study needs to include: the position, complexity and size of the VSD with the site of infarction (anterior versus inferior) as a useful guide to the VSD position 2. Colour flow Doppler has a high sensitivity and specificity for detecting septal rupture and is particularly useful in excluding acute mitral regurgitation secondary to papillary muscle dysfunction, which is the usual differential diagnosis. 3. Assess the function and size of both ventricles 4. Assess the right ventricular systolic pressure from the tricuspid regurgitant velocity and estimation of right atrial pressure. It is often not possible for an accurate left-to-right shunt calculation at the bedside. For surgical intervention, assessment of right ventricular function is of paramount importance. Care should be taken not to include any left to right VSD jet in the measurement of the TR, which could seriously overestimate the RVSP. Rarely a VSD can co-exist with a pseudoaneurysm, when contained free wall rupture and septal rupture occur simultaneously. In these challenging cases, 3D echo can be very useful to delineate the different pathologies. 3-dimensional echocardiography can provide unique views of VSDs from the left ventricular (LV) side, allowing complete assessment of their circumference and spatial orientations to other anatomic structures. 3DE provides excellent visualization of various types of VSDs. From an LV en face projection, the positions, sizes, and shapes of VSDs can be accurately determined. Dynamic 3D TEE provides important 214
Anatomical Imaging Using 3D Echocardiography in Patients with Mechanical Complications additional diagnostic information and is a useful technique in the assessment of patients with VSD. It enhances the understanding of the anatomy of the lesion and should be an important process in the choice of therapeutic options (device closure or surgical procedures). Combined with 2D techniques, it is highly reliable for the preoperative assessment of VSD (Figure 7,8,9). ACKNOWLEDGEMENT This work received financial support through the project entitled CERO Career profile: Romanian Researcher, grant number POSDRU/159/1.5/S/135760, cofinanced by the European Social Fund for Sectoral Operational Programme Human Resources Development 2007-2013. BIBLIOGRAPHY 1. Assi ER, Tak T: Posterior myocardial infarction complicated by rupture of the posteromedial papillary muscle. J HeartValve Dis 1999, 8:565-566. 2. Ginghina C. Mic tratat de cardiologie, Editura Academiei Romane, 2010 3. Clements SD Jr, Story WE, Hurst JW, Craver JM, Jones EL: Ruptured papillary muscle, a complication of myocardial infarction: clinical presentation, diagnosis, and treatment. Clin Cardiol 1985, 8:93-103. 4. Fasol R, Lakew F, Wetter S: Mitral repair in patients with a ruptured papillary muscle. Am Heart J 2000, 139:549-554. 5. Hutchins GM. Rupture of the interventricular septum complicating myocardial infarction: pathological analysis of 10 patients with clinically diagnosed perforations. Am Heart J1979; 97:165 173. 6. Muraru Denisa, Zakja Edlira, Gianfagna Pasquale, Badano Luigi -Real-time 3D echocardiographic visualization of a large interventricular septal defect complicating acute antero-apical myocardial infarction 7. Mark J Monaghan-Role of real time 3D echocardiography in evaluating the left ventricle 8. K. Hadeed, S. Hascoet, 3D transthoracic echocardiography to assess ventricular septal defect anatomy and severity 215