Echocardiographic imaging of procedural complications during balloon-expandable transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) using a balloon-expandable valve is an accepted alternative to surgical replacement for severe, symptomatic aortic stenosis in high risk or inoperable patients. Intraprocedural transesophageal echocardiography (TEE) offers real-time imaging guidance throughout the procedure and allows for rapid and accurate assessment of complications and procedural results. The value of intraprocedural TEE for TAVR will likely increase in the future as this procedure is performed in lower surgical risk patients, who also have lower risk for general anesthesia, but a greater expectation of optimal results with lower morbidity and mortality. This imaging compendium from the PARTNER (Placement of Aortic Transcatheter Valves) trials is intended to be a comprehensive compilation of intraprocedural complications imaged by intraprocedural TEE and diagnostic tools to anticipate and/or prevent their occurrence.

Does the aortic annulus undergo conformational change throughout the cardiac cycle? A systematic review

Accurate annular sizing in transcatheter aortic valve implantation (TAVI) planning is essential. It is now widely recognized that the annulus is an oval structure in most patients, but it remains unclear if the annulus undergoes change in size and shape during the cardiac cycle that may impact prosthesis size selection. Our aim was to assess whether the aortic annulus undergoes dynamic conformational change during the cardiac cycle and to evaluate possible implications for prosthesis size selection. We performed a systematic search in PubMed and Embase databases and reviewed all available literature on aortic annulus measurements in at least two cardiac phases. Twenty-nine articles published from 2001 to 2014 were included. In total, 2021 subjects with and without aortic stenosis were evaluated with a mean age ranging from 11 ± 3.6 to 84.9 ± 7.2 years. Two- and three-dimensional echocardiography was performed in six studies each, magnetic resonance imaging was used in one and computed tomography in 17 studies. In general, the aortic annulus was more circular in systole and predominantly oval in diastole. Whereas the annular long-axis diameter showed insignificant change throughout the cycle, the short-axis diameter, area, and perimeter were significantly larger in systole compared with diastole. Hence, the aortic annulus does undergo dynamic changes during the cardiac cycle. In patients with large conformational changes, diastolic compared with systolic measurements can result in undersizing TAVI prostheses. Due to the complex annular anatomy and dynamic change, three-dimensional assessment in multiple phases has utmost importance in TAVI planning to improve prosthesis sizing.

Acquired Gerbode defect following endocarditis of the tricuspid valve: a case report and literature review

The Gerbode’s defect is a communication between the left ventricle and right atrium. It is usually congenital, but rarely is acquired, as a complication of endocarditis, myocardial infarction, trauma, or after previous cardiac surgery. The acquired Gerbode defect with involvement of the tricuspid valve acquired after bacterial endocarditis can be challenging to repair. We present a rare case of young woman, with endocarditis of the tricuspid valve and acquired Gerbode defect without previous cardiac surgery. She underwent successful surgical closure of the Gerbode defect and reconstruction of the septal leaflet of the tricuspid valve using a an autologous pericardial patch. A total of 20 other cases were reported with acquired Gerbode defect due to endocarditis in patients without previous cardiac surgery. Three other cases presented acquired Gerbode defect due to myocardial infarction and two due to chest trauma. Another series of 62 patients presented acquired Gerbode defect after previous cardiac surgery. Surgical treatment is always feasible with excellent outcome. However the percutanous transcatheter closure remains an excellent option especially in high risk patients.

Prognostic significance of persistent restrictive filling pattern after cardiac resynchronization therapy

BACKGROUND

Cardiac resynchronization therapy (CRT) may improve left ventricular (LV) diastolic dysfunction as well as systolic dysfunction. Diastolic dysfunction is a key for prognosis in patients with heart failure; therefore, we aimed to clarify the impact of CRT on diastolic function and prognosis.

METHODS

In 67 patients who underwent CRT, LV diastolic function was assessed by pulsed Doppler transmitral flow pattern at baseline and 1 week after CRT, and classified into restrictive filling pattern (RFP) and non-RFP groups. Volume responders were defined by reduction of LV end-systolic volume >15% at 6 months after CRT. The clinical endpoint comprised death from any cause or unplanned hospitalization for a major cardiovascular event (MACE).

RESULTS

During the follow-up period (479 ± 252 days), 26 patients (38.8%) had reached the endpoint of MACE. In Cox proportional hazard analyses, RFP at 1 week after CRT was associated with the endpoints independently of age and New York Heart Association (NYHA) class IV at baseline. Thirty (44.8%) patients were identified as volume responders, who had better prognosis than non-responders. Patients were classified into 4 groups based on their filling pattern at 1 week after CRT and volume responses. The worst prognosis was observed in the RFP and non-responder group, and the best was observed in the non-RFP and responder group. For the remaining 2 groups with intermediate prognosis, the RFP and responder group showed poorer prognosis compared to the non-RFP and non-responder group.

CONCLUSIONS

Persistent RFP after CRT may be a strong prognostic predictor, which should be treated with more intensive therapy to improve the prognosis of patients following CRT.

Multiple intracardiac tumors secondary to non-Hodgkin lymphoma

Primary tumors of the heart are rare and are usually benign. Disseminated malignancies and lymphomas rarely involve the heart. Non-Hodgkin lymphomas (NHL) are one of the common hematological malignancies that can affect the heart usually in the form of pericardial effusion. Involvement as intracardiac masses in NHL is extremely rare and usually described in autopsy series. We report a case of NHL and massive intracardiac involvement diagnosed on echocardiographic assessment. Primary cardiac NHL is extremely rare and accounts for 1-2 % of primary cardiac tumors involving the right versus left atrium at a ratio of about 8:1 (Ceresoli et al., Cancer 80:1497-1506, 1997; Delmas-Marsalet et al., Nouv Rev Fr Hematol 37:223-230, 1995). The intracardiac secondaries in NHL are extremely rare. They are usually described in autopsy series. We report the detection of secondaries in the cardiac chambers, on interatrial septum and in atrioventricular groove, diagnosed by transthoracic echocardiography.

Cardiac sarcoidosis: diagnosis and management

Cardiac sarcoidosis is one of the most serious and unpredictable aspects of this disease state. Heart involvement frequently presents with arrhythmias or conduction disease, although myocardial infiltration resulting in congestive heart failure may also occur. The prognosis in cardiac sarcoidosis is highly variable, which relates to the heterogeneous nature of heart involvement and marked differences between racial groups. Electrocardiography and echocardiography often provide the first clue to the diagnosis, but advanced imaging studies using positron emission tomography and MRI, in combination with nuclear isotope perfusion scanning are now essential to the diagnosis and management of this condition. The identification of clinically occult cardiac sarcoidosis and the management of isolated and/or asymptomatic heart involvement remain both challenging and contentious. Corticosteroids remain the first treatment choice with the later substitution of immunosuppressive and steroid-sparing therapies. Heart transplantation is an unusual outcome, but when performed, the results are comparable or better than heart transplantation for other disease states. We review the epidemiology, developments in diagnostic techniques and the management of cardiac sarcoidosis.

Impact of right ventricular involvement on the prognosis of takotsubo cardiomyopathy

BACKGROUND

Previous studies showed that patients with takotsubo cardiomyopathy had a higher long-term mortality rate than the general population and the incidence of in-hospital complications was higher in takotsubo cardiomyopathy with than without right ventricular (RV) involvement. This study was performed to investigate the long-term prognostic impact of RV involvement in takotsubo cardiomyopathy.

METHODS AND RESULTS

The clinical data of 113 patients (72.7 ± 11.4 years old, 84 females) with takotsubo cardiomyopathy were studied retrospectively. The patients were divided into two groups according to the presence (biventricular group, n = 21, 18.6%) or absence (classical group, n = 92, 81.4%) of RV involvement assessed by initial echocardiography. The end point was a composite of all-cause death, re-hospitalization due to heart failure, and recurrence of takotsubo cardiomyopathy. The in-hospital mortality rate was significantly higher in the biventricular group than the classical group (14.3 vs. 1.1%, respectively, P = 0.02). Kaplan-Meier analysis indicated a significantly lower event-free survival rate in the biventricular group than the classical group (log-rank, P < 0.001). On multivariate analysis, RV involvement was the only independent predictor of the end point (HR: 2.73, P = 0.026).

CONCLUSION

The rates of in-hospital and long-term events were significantly higher in takotsubo cardiomyopathy with than without RV involvement, and RV involvement was the independent predictor of the poor prognosis.

Unicuspid unicommissural aortic valve: an extremely rare congenital anomaly

Unicuspid aortic valve is a rare congenital malformation that usually presents in the 3rd to 5th decade of life-and usually with severe aortic stenosis or regurgitation. It often requires surgical correction. Diagnosis can be made with 2- or 3-dimensional transthoracic or transesophageal echocardiography, cardiac computed tomography, or cardiac magnetic resonance imaging. We report the case of a 31-year-old man who presented with dyspnea on exertion due to severe aortic stenosis secondary to a unicuspid unicommissural aortic valve. After aortic valve replacement, this patient experienced complete heart block that required the placement of a permanent pacemaker.

Impact of Elevated D-Dimer on Diagnosis of Acute Aortic Dissection With Isolated Neurological Symptoms in Ischemic Stroke

BACKGROUND

Plasma D-dimer is known to be a useful clinical marker of thrombogenic status, and D-dimer is used as a diagnostic marker for acute aortic dissection (AAD). Little is known, however, regarding the clinical value of D-dimer for diagnosis of asymptomatic AAD in patients with ischemic stroke. We investigated whether D-dimer could be used for early diagnosis of AAD with isolated neurological symptoms in ischemic stroke patients.

METHODS AND RESULTS

We evaluated a total of 1,236 consecutive patients with symptomatic ischemic stroke without chest or back pain who underwent either head computed tomography or magnetic resonance imaging. D-dimer was measured within 24 h after onset. There were 9 patients with Stanford type A AAD and they had significantly higher D-dimer than the patients without AAD (mean, 46.47±54.48 μg/ml; range, 6.9-167.1 μg/ml vs. 2.33±3.58 μg/ml, 0.3-57.9 μg/ml, P<0.001). When a cut-off of 6.9 μg/ml was adopted for d-dimer on the basis of receiver operating characteristics analysis, the sensitivity and specificity for AAD were 100% and 94.8%, respectively, while the positive and negative predictive values were 14.7% and 100%, respectively.

CONCLUSIONS

D-dimer might be a useful marker for the early diagnosis of AAD with isolated neurological symptoms in ischemic stroke patients. Whole-body contrast-enhanced computed tomography should be performed in ischemic stroke patients who have high D-dimer.

Application of three-dimensional speckle tracking echocardiography to assess left ventricular regional work using wall tension-regional area loop

Three-dimensional (3-D) speckle tracking echocardiography allows us to track a change in regional endocardial surface area. The change of regional area during a cardiac cycle should be useful for assessing left ventricular regional work. We investigated the feasibility of assessing regional work, calculated as the area within the wall tension-regional area (T-A) loop using 3-D echocardiography. Three-dimensional full-volume images were acquired using 3-D echocardiography (Artida, Toshiba) at baseline and during brief occlusion of the left circumflex coronary artery in eight dogs. Wall tension was calculated according to Laplace's law for a spherical model. Area change ratio (in %) determined by area tracking was transformed into a change of regional area (in cm2) by a custom software. We calculated the area within the T-A loop (TAA) in the area under transient ischemia (risk area) and the remote area as regional work and validated the T-A loop method by comparing the global integral of TAA with the total work assessed by the pressure-volume loop. During coronary occlusion, regional work for the risk area significantly decreased (baseline vs. occlusion, 26.8 ± 10.7 vs. 18.4 ± 7.8 mmHg·cm3; P < 0.05), whereas that for the remote area did not change. The global integral of TAA closely correlated with the total work assessed by the pressure-volume loop ( r = 0.91, P < 0.0001). The wall T-A loop reflected regional dysfunction caused by myocardial ischemia. This analysis using 3-D speckle tracking echocardiography might be useful to quantify left ventricular regional work.

Acquired left ventricle-to-right atrium shunt: clinical implications and diagnostic dilemmas

BACKGROUND

The acquired left ventricle-to-right atrium (LV-RA) shunt (Gerbode defect) is rare but it can sometimes be a critical condition. The diagnosis is quite challenging largely due to its exotic anatomic features and diagnostic difficulties. This study aims to present the clinical features and diagnostic solutions of this rare lesion.

METHODS

Data source was based on a comprehensive literature retrieval of acquired LV-RA shunts of 1990-2014.

RESULTS

Most of the acquired LV-RA shunts are of either a postoperative or an infective etiology. Transthoracic echocardiography showed a 62.2% accurate diagnosis, 13.4% inclusive diagnosis, 9.8% missed diagnosis, and 14.5% misdiagnosis rate. The accurate diagnostic rate of transthoracic echocardiography was significantly lower than that of the transesophageal echocardiography or cardiac catheterization. The LV-RA shunts are often misinterpreted as mitral regurgitation, pulmonary hypertension, tricuspid regurgitation, Valsalva aneurysm rupture, and subaortic/high perimembrane/residual ventricular septal defect. Surgical, interventional, and conservative treatments were applied in 57.8, 24.4, and 17.8% patients, respectively. Prognosis showed an event-free survival of 85%, a comorbidity of 9.1%, and a mortality of 13.6%.

CONCLUSIONS

A high jet detected in the right atrium with uncertain origin and course has to appeal to additional diagnostic techniques including transesophageal echocardiography, cardiac catheterization, or cardiac magnetic resonance imaging for differential diagnoses. Small restrictive shunts are preferred with conservative treatments, high-risk patients are candidates of interventional therapy, and the patients with unstable hemodynamics warrant an open heart surgery. Careful operative maneuver, good control of intracardiac infection, preservation of heart function, etc., are mandatory for the prevention of the development of an acquired LV-RA shunt.

Relationship between glycosylated hemoglobin A1c and coronary flow reserve in patients with Type 2 diabetes mellitus

Type 2 diabetes mellitus patients are at increased risk for macrovascular and microvascular complications. Both in vivo and in vitro studies of small arteries and arterioles of diabetic subjects demonstrate impaired endothelial function without anatomic lesions. Coronary flow reserve (CFR) is a surrogate marker of coronary microcirculatory endothelial function in diabetic patients without significant stenosis of the associated epicardial coronary artery. Glycosylated hemoglobin A1c is related to likelihood of occurrence of microvascular events. The objective of this article is to report on recent developments in multiple noninvasive techniques to assess CFR and their use in aiding the understanding of the relationship of CFR, glycemic control and cardiovascular outcomes.

Two-dimensional blood flow vectors obtained with bidirectional Doppler ultrasound

Precise measurement of blood flow is important because blood flow closely correlates formation of thrombus and atherosclerotic plaque. Among clinically applied modalities for blood flow measurement, color Doppler ultrasound shows two-dimensional (2D) distribution of one-dimensional blood flow component along the ultrasound beam. In the present study, 2D blood flow vector is obtained with high temporal and bidirectional Doppler ultrasound technique. Linear array probe with the central frequency of 7.5 MHz and an ultrasound data acquisition system with 128 transmit and 128 receive channels were equipped. Frame rate of 5 kHz was achieved by parallel receive beam forming with a wide transmitted wave. The flow velocity was measured from two different angles by beam steering. The interval of two measurements was 0.8 msec and it was considered as almost one moment to obtain 2D blood flow vector. B-mode image and 2D blood flow vector of the pulsatile flow in a carotid artery model showed small vortex at the bifurcation area. The method was also applied for visualization of in vivo blood flow vector in human carotid arteries. 2D blood flow measurement may predict the risk area of thrombus and plaque formation induced by abnormal blood flow.

Myocardial Calcification with a Latent Risk of Congestive Heart Failure in a Patient with Apical Hypertrophic Cardiomyopathy

Myocardial calcification is rare. An 88-year-old man who had previously been diagnosed with apical hypertrophic cardiomyopathy exhibited left ventricular asynergy on echocardiography before undergoing cholecystectomy. Computed tomography revealed severe calcification in the apical region of the left ventricular myocardium, although the coronary arteries were intact and the hemodynamics on right heart catheterization were normal. The cause of the left ventricular asynergy appeared to be myocardial calcification, thought to be the result of rheumatic fever based on the patient's past history. Stress echocardiography showed a latent risk for the development of heart failure due to the distensibility of the calcified left ventricular myocardium.

Systolic Flow Reversal in a Case of Mid-Ventricular Obstructive Hypertrophic Cardiomyopathy

A 69-year-old man presented to our hospital with chest pain. Two-dimensional transthoracic echocardiography showed hypertrophy of the left ventricle, mid-ventricular obstruction and an apical aneurysm. Color-flow imaging at the obstruction site on the apical four-chamber view demonstrated systolic flow reversal in addition to a paradoxical jet flow. The systolic flow reversal may have been caused by a decreased apical contractility and pressure during systole.

Decreased diastolic wall strain is associated with adverse left ventricular remodeling even in patients with normal left ventricular diastolic function

Background

The pathophysiology of diastolic dysfunction is complex, but can be simply described as impaired LV myocardial relaxation and/or increased LV stiffness. The objective of this study is to clarify true normal left ventricular (LV) diastolic function and early stage of diastolic dysfunction before relaxation abnormality develops in patients with normal LV diastolic function using simple diastolic wall strain (DWS) in South Korea.

Methods

DWS which is a non-invasive, load-independent, and reproducible estimator of LV stiffness using two-dimensional echocardiography using the difference between posterior wall thickness in systole and diastole to approximate LV stiffness. A total of 349 consecutive patients with normal LV diastolic function by echocardiography were enrolled. According to DWS, patients were divided into two groups: high DWS (≥median 175) vs. low DWS (<median 174).

Results

Patients with low DWS were more obese and showed higher blood pressure, and had more prevalent hypertension and hyperlipidemia. In addition, those with low DWS had higher LV end-systolic volume, LV mass index, E/E’ and lower ejection fraction and E’ velocity. Among them, higher LVESV and LVMI were independently associated with low DWS.

Conclusions

These data suggests that simple DWS might be helpful in identifying a subgroup of subtle diastolic dysfunction. Our data suggest that early change of diastolic dysfunction might start with abnormal LV geographic changes preceding functional changes.

Different characteristics of heart failure due to pump failure and bradyarrhythmia

Background

Heart failure (HF) can be caused by left ventricular (LV) pump failure as well as by bradyarrhythmias. Hemodynamic differences between HF by LV pump failure and that by bradyarrhythmia have not been fully investigated. We hypothesized that HF by LV pump failure could be associated with both reduced cardiac output (CO) and increased LV filling pressure due to associated LV diastolic dysfunction, whereas HF by bradyarrhythmia could be associated with reduced CO but only modestly increased LV filling pressure due to the absence of LV diastolic dysfunction.

Methods

In 39 patients with HF by LV pump failure (LV ejection fraction <35 %), 24 with HF by bradyarrhythmia, and 22 normal controls, LV volume, ejection fraction, stroke volume, left atrial volume, and early diastolic mitral valve flow to tissue annular velocity ratio (E/E′) were measured by echocardiography.

Results

Compared to patients with HF by LV pump failure, those with HF by bradyarrhythmia had significantly lower heart rates, less LV dilatation, preserved LV ejection fraction, preserved stroke volume, similarly reduced cardiac index (1.8 ± 0.4 vs. 1.6 ± 0.4 L/min/m², n.s.), preserved LV diastolic function (E′) (4.4 ± 2.1 vs. 7.1 ± 2.9 cm/s, p < 0.001), less dilated end-systolic LA volume, and preserved E/E′ (24 ± 10 vs. 13 ± 7, p < 0.001).

Conclusions

HF by LV pump failure is characterized by both significantly reduced CO and increased LV filling pressure, whereas HF by bradyarrhythmia is characterized by a similar reduction in CO but only modestly increased LV filling pressure.

Role of cardiovascular echo in patients with Takayasu arteritis

INTRODUCTION

Takayasu arteritis is an important differential diagnosis in young female patients presenting with fever, fatigue, hypertension, and/or neck pain.

ECHOCARDIOGRAPHIC FEATURES

Aortic arch branch vessels are frequently affected and the carotid artery can have diffuse, homogeneous wall thickening, known as the 'macaroni sign'. The descending aorta can be stenotic with 'pseudo-coarctation'.

CONCLUSION

Cardiovascular echo plays an important role in the screening and characterization of arterial lesions in patients with Takayasu arteritis.

A simple and accurate method for computer-aided transapical aortic valve replacement

BACKGROUND AND PURPOSE

Transapical aortic valve replacement (TAVR) is a recent minimally invasive surgical treatment technique for elderly and high-risk patients with severe aortic stenosis. In this paper, a simple and accurate image-based method is introduced to aid the intra-operative guidance of TAVR procedure under 2-D X-ray fluoroscopy.

METHODS

The proposed method fuses a 3-D aortic mesh model and anatomical valve landmarks with live 2-D fluoroscopic images. The 3-D aortic mesh model and landmarks are reconstructed from interventional X-ray C-arm CT system, and a target area for valve implantation is automatically estimated using these aortic mesh models. Based on template-based tracking approach, the overlay of visualized 3-D aortic mesh model, landmarks and target area of implantation is updated onto fluoroscopic images by approximating the aortic root motion from a pigtail catheter motion without contrast agent. Also, a rigid intensity-based registration algorithm is used to track continuously the aortic root motion in the presence of contrast agent. Furthermore, a sensorless tracking of the aortic valve prosthesis is provided to guide the physician to perform the appropriate placement of prosthesis into the estimated target area of implantation.

RESULTS

Retrospective experiments were carried out on fifteen patient datasets from the clinical routine of the TAVR. The maximum displacement errors were less than 2.0mm for both the dynamic overlay of aortic mesh models and image-based tracking of the prosthesis, and within the clinically accepted ranges. Moreover, high success rates of the proposed method were obtained above 91.0% for all tested patient datasets.

CONCLUSION

The results showed that the proposed method for computer-aided TAVR is potentially a helpful tool for physicians by automatically defining the accurate placement position of the prosthesis during the surgical procedure.

Evaluation of diastolic function by three-dimensional volume tracking of the mitral annulus with cardiovascular magnetic resonance: comparison with tissue Doppler imaging

BACKGROUND

Measurement of mitral annulus (MA) dynamics is an important component of the evaluation of left ventricular (LV) diastolic function; MA velocities are commonly measured using tissue Doppler imaging (TDI). This study aimed to examine the clinical potential of a semi-automated cardiovascular magnetic resonance (CMR) technique for quantifying global LV diastolic function, using 3D volume tracking of the MA with conventional cine-CMR images.

METHODS

124 consecutive patients with normal ejection fraction underwent both clinically indicated transthoracic echocardiography (TTE) and CMR within 2 months. Interpolated 3D reconstruction of the MA over time was performed with semi-automated atrioventricular junction (AVJ) tracking in long-axis cine-CMR images, producing an MA sweep volume over the cardiac cycle. CMR-based diastolic function was evaluated, using the following parameters: peak volume sweep rates in early diastole (PSRE) and atrial systole (PSRA), PSRE/PSRA ratio, deceleration time of sweep volume (DTSV), and 50% diastolic sweep volume recovery time (DSVRT50); these were compared with TTE diastolic measurements.

RESULTS

Patients with TTE-based diastolic dysfunction (n = 62) showed significantly different normalized MA sweep volume profiles compared to those with TTE-based normal diastolic function (n = 62), including a lower PSRE (5.25 ± 1.38 s-1 vs. 7.72 ± 1.7 s-1), a higher PSRA (6.56 ± 1.99 s-1 vs. 4.67 ± 1.38 s-1), a lower PSRE/PSRA ratio (0.9 ± 0.44 vs. 1.82 ± 0.69), a longer DTSV (144 ± 55 ms vs. 96 ± 37 ms), and a longer DSVRT50 (25.0 ± 11.0% vs. 15.6 ± 4.0%) (all p < 0.05). CMR diastolic parameters were independent predictors of TTE-based diastolic dysfunction after adjusting for left ventricular hypertrophy, hypertension, and coronary artery disease. Good correlations were observed between CMR PSRE/PSRA and early-to-late diastolic annular velocity ratios (e'/a') measured by TDI (r = 0.756 to 0.828, p < 0.001).

CONCLUSIONS

3D MA sweep volumes generated by semi-automated AVJ tracking in routinely acquired CMR images yielded diastolic parameters that were effective in identifying patients with diastolic dysfunction when correlated with TTE-based variables.

Left ventricular to right atrial shunt (Gerbode defect): congenital versus acquired

Introduction

Congenital left ventricular to right atrial (LV-RA) shunt (Gerbode defect) is rare, while acquired LV-RA shunt has been increasingly reported. As yet, systematically incorporated data of the LV-RA shunt have not been presented.

Aim

To present the clinical features, diagnostic challenge and management strategies of congenital and acquired LV-RA shunts.

Material and methods

The data source was based on a comprehensive literature retrieval of the LV-RA shunt in the period 1990–2013.

Results

In comparison with the acquired Gerbode defect, the congenital Gerbode defect group of patients were younger and were associated more often with additional congenital disorders. Previous cardiac surgery and infective endocarditis were the two major aetiologies of the occurrence of the acquired shunts. Paravalvular abscess was associated in 10.2% and atrioventricular block in 13.6% of the acquired group patients. Transoesophageal echocardiography showed a higher diagnostic accuracy, lower missed diagnosis and lower inclusive diagnosis rates, in comparison to transthoracic echocardiography, but the misdiagnosis rates of the two modalities did not differ from each other. Four (4.5%) of the acquired group patients were complicated by atrioventricular block following surgical or interventional closure of the shunt. Eight (9.1%) patients died in the acquired group, but no patient died in the congenital group.

Conclusions

The diagnosis of an LV-RA shunt is quite challenging, especially in the context of coexisting abnormalities including an additional intracardiac shunt, tricuspid regurgitation, pulmonary artery hypertension and infective endocarditis, which have to be carefully differentiated from the shunt by further investigations. A better control of infective complications and careful manoeuvres during surgery may help to keep the LV-RA-sensitive septum intact.

Assessment of cardiac sarcoidosis with advanced imaging modalities

Sarcoidosis is a chronic systemic disease of unknown etiology that is characterized by the presence of noncaseating epithelioid granulomas, usually in multiple organs. Several studies have shown that sarcoidosis might be the result of an exaggerated granulomatous reaction after exposure to unidentified antigens in genetically susceptible individuals. Cardiac involvement may occur and lead to an adverse outcome: the heart mechanics will be affected and that causes ventricular failure, and the cardiac electrical system will be disrupted and lead to third degree atrioventricular block, malignant ventricular tachycardia, and sudden cardiac death. Thus, early diagnosis and treatment of this potentially devastating disease is critically important. However, sensitive and accurate imaging modalities have not been established. Recent studies have demonstrated the promising potential of cardiac magnetic resonance imaging (MRI) and (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)F-FDG PET) in the diagnosis and assessment of cardiac sarcoidosis (CS). In this review, we discuss the epidemiology, etiology, histological findings, and clinical features of sarcoidosis. We also introduce advanced imaging including (18)F-FDG PET and cardiac MRI as more reliable diagnostic modalities for CS.

Low diastolic wall strain is associated with raised post-exercise E/E' ratio in elderly patients without obvious myocardial ischemia

BACKGROUND

It has been reported that the diastolic wall strain (DWS) inversely correlates with the myocardial stiffness constant. The ratio of early diastolic transmitral flow velocity to annulus velocity (E/E') correlates with the left ventricular (LV) filling pressure. Increased LV wall stiffness is thought be associated with increased LV filling pressure after exercise. The purpose of this study was to evaluate the correlation between the DWS and post-exercise E/E' in elderly patients without obvious myocardial ischemia.

METHODS

Fifty-eight elderly patients (age = 74 ± 6 years) who underwent treadmill stress echocardiography were studied. All patients had normal LV wall motion at rest, and patients with exercise-induced wall motion abnormality were excluded. The DWS was calculated as follows: DWS = (PWTs - PWTd)/PWTs, where PWTs is the LV posterior wall thickness at end-systole and PWTd is that at end-diastole. As previously reported, DWS ≤ 0.33 was defined as low DWS and E/E' ≥15.0 was defined as a marker of increased LV filling pressure.

RESULTS

Eighteen patients had low DWS. Patients with low DWS had greater post-exercise E/E' (17.9 ± 3.2 vs. 12.8 ± 3.3, p < 0.0001). The DWS was inversely and strongly correlated with post-exercise E/E' (r (2) = 0.534, p < 0.0001). Low DWS predicted the development of raised post-exercise E/E' ≥15.0 with a positive predictive value of 94 % and a negative predictive value of 85 %.

CONCLUSION

In elderly patients without obvious myocardial ischemia, the DWS correlates strongly and inversely with post-exercise E/E'. Patients with low DWS were likely to develop raised E/E' after exercise.

Association of left atrial reservoir function with left atrial structural remodeling related to left ventricular dysfunction in asymptomatic patients with hypertension: evaluation by two-dimensional speckle-tracking echocardiography

Left atrial (LA) structural and functional abnormalities are vital steps on the pathway toward heart failure with preserved ejection fraction in asymptomatic patients. The purpose of this study was to assess the relationship of LA function, particularly reservoir function, with LA structural remodeling related to the left ventricular (LV) dysfunction in asymptomatic patients with hypertension (HT) using conventional, tissue Doppler, and 2-D speckle-tracking echocardiography. Fifty age-matched healthy individuals and 140 patients with HT, including 75 with LA volume index (LAVI)<29 ml/m2 (normal LA group) and 65 with LAVI≥29 ml/m2 (large LA group), were enrolled. We defined peak early diastolic transmitral flow velocity/peak early diastolic mitral annular motion velocity (E/e')/peak systolic LA strain (S-LAs) as LA diastolic stiffness. The LV mass index, relative LV wall thickness, peak atrial systolic transmitral flow velocity, LA total, active, and passive emptying volume indexes, and E/e'/S-LAs were greatest, and S-LAs, peak early diastolic LA strain, peak systolic LV longitudinal strain and circumferential strain rate, and peak early diastolic LV radial strain rate were lower in the large LA group compared with control and/or normal LA group. Multivariate linear regression analysis revealed that aging, LA remodeling, and LV systolic and diastolic dysfunction are defined as strong predictors related to increased LA diastolic stiffness in the large LA group. HT alters LA dynamics significantly, with resultant increased LA volume and diastolic stiffness related to LV diastolic and systolic dysfunction, even in asymptomatic patients. Earlier treatment with renin–angiotensin system inhibitors may improve abnormal LA-LV interaction in this patient population.

FINITE ELEMENT MODELING OF THE HUMAN MITRAL VALVE: IMPLICATIONS OF MORPHOLOGIES AND DYNAMICS OF THE ANNULUS AND THE CHORDAE TENDINEAE

Objectives: To investigate the influences caused by special morphologies and dynamics of the substructures of mitral valve by the explicit finite element program LS-DYNA. Methods: A new finite element model for the mitral apparatus characterized by layered structure of leaflets tissue, saddle shape and contraction of annulus, an approximately accurate morphology of chordae tendineae was developed. The coaptation length, leaflets stress and strain of the present model were compared with those of two auxiliary models, one with planar annulus and the other with fixed annulus. The tensile function and force distribution of chordae tendineae were analyzed in the models with and without chordae tendineae. Results: The stretch ratios computed by the present model were most closely to the experimental data. The leaflets instantly turned over to the atrial side and larger load was observed in the model without chordae tendineae. Besides, tensile force was highly correlated with average diameter of chordae tendineae (r = 0.965). Conclusion: The saddle shape of annulus benefits valve coaptation and the contraction of annulus could help decrease loads on leaflets and prevent stress concentrating excessively. Chordae tendineae could bear partial loads on the leaflets, and prevent the leaflets to turn over to the side of the atrium and help the valve close successfully.

The aortic valve: structure, complications and implications for transcatheter aortic valve replacement

The aortic valve operates in a complex haemodynamic environment, opening and closing over 100,000 times a day. When complications arise, such as aortic stenosis, prognosis can be very poor, leading to death within the first few years. Surgical valve replacement is currently the standard treatment for aortic stenosis. A thorough understanding of the anatomy and function of the native valve is imperative when developing a prosthetic replacement that can withstand the complex demands of the heart. This review focuses on the anatomy, structure and disease of the aortic valve and the implications for a transcatheter aortic valve replacement (TAVR). Current complications with TAVR, such as major vascular bleeding, conduction disturbances and patient-prosthesis mismatch (PPM), can be overcome by reducing the delivery profile and through the use of more accurate imaging technologies to work towards a fully functional and durable prosthesis.

Current status of the hybrid approach for the treatment of hypoplastic left heart syndrome

The hybrid approach for hypoplastic left heart syndrome (HLHS), consisting of bilateral pulmonary artery banding and ductal stenting, has emerged as an alternative to the traditional Norwood approach. This approach defers open heart surgery to beyond the neonatal period, which is believed to reduce postoperative mortality and morbidity and improve neurological development as compared with the conventional approach. However, there have been no scientific studies supporting these hypotheses. Recently, there seems to be a tendency that many centers recommend the hybrid approach as an interim procedure to rescue preoperative high-risk patients. Currently, the decision to adopt the hybrid approach or the Norwood approach seemed to be based on the preference of congenital heart surgeons and cardiologists. Further investigation including a randomized multi-center study would allow a scientific decision as to which approach is more appropriate for the patient with HLHS.

Patient with pseudo-retrograde coronary flow in the normal right coronary artery and left circumflex artery: pitfall of retrograde coronary flow to detect coronary artery occlusion

A 75-year-old lady with hypertension and paroxysmal atrial fibrillation underwent echocardiography to evaluate cardiac function. Transthoracic Doppler echocardiography revealed retrograde coronary flow in the right coronary artery (RCA) and left circumflex artery (LCX). Computed tomographic coronary angiography demonstrated normal but tortuous coronary arteries. This tortuosity of the coronary arteries was thought be a cause of pseudo-retrograde coronary flow in the RCA and LCX. The present case demonstrates a pitfall of retrograde coronary flow for the detection of coronary artery occlusion in daily practice.

Assessment of cyclic changes in the diameter of the aortic annulus using speckle-tracking trans-esophageal echocardiography

It is uncertain whether dynamic variation in the diameter of the aortic annulus occurs during the cardiac cycle in humans. The purpose of this study was to analyze cyclic changes of the aortic annulus using speckle-tracking trans-esophageal echocardiography. The subjects were 40 patients with aortic stenosis and 40 controls. Absolute and relative changes in the diameter of the aortic annulus and the times at which the maximum and minimum diameters occurred during the cardiac cycle were determined using speckle-tracking trans-esophageal echocardiography. The maximum and minimum diameters were 22.9 ± 2.7 and 20.0 ± 2.9 mm, respectively, in controls. The change in diameter of the aortic annulus was 2.9 ± 0.7 mm, and the relative change was 12.9 ± 3.5%. The maximum aortic annulus diameter was reached at the onset of aortic valve opening, and the minimum diameter occurred in the rapid filling phase. The change in diameter of the aortic annulus was significantly smaller (2.2 ± 0.6 mm vs. 2.9 ± 0.7 mm, p < 0.0001), and the time to reach the maximum diameter was significantly longer (98.5 ± 17.5 ms vs. 83.4 ± 18.2 ms, p = 0.0004), in the aortic stenosis group than in the control group. The study found that dynamic changes of the aortic annulus occur in the cardiac cycle and can be measured using speckle-tracking trans-esophageal echocardiography. We also found that aortic stenosis has an effect on the extent and timing of these changes. This suggests that accurate assessment of aortic annulus diameter requires consideration of the timing of the cardiac cycle.