Chordal tethering: a unique cause of structural mitral regurgitation in dilated cardiomyopathy

Mitral regurgitation in dilated cardiomyopathy is usually considered "functional," and many such patients are treated medically. Surgery is often offered as a last resort in select patients who have failed medical therapy. We report a patient with dilated cardiomyopathy with ventricular tachycardia and ventricular dyssynchrony and "structural mitral regurgitation" due to chordal tethering, which was managed surgically using a minimally invasive approach.     

An Approach to the Stepwise Management of Severe Mitral Regurgitation with Optimal Cardiac Pacemaker Function

Right ventricular apical pacing may cause or worsen mitral regurgitation (MR). Potential mechanisms for this adverse sequelae include intraventricular dyssynchrony, altered papillary muscle function, pacing-induced cardiomyopathy with left ventricular dilation, and annular dilation. In contrast, biventricular (BiV) pacing may improve MR presumably by opposing the negative effects. Whether or not left ventricular lead location is important in treating mitral regurgitation in patients with pacemakers is unknown.We report a case of severe MR and left ventricular (LV) systolic failure in a patient with right ventricular pacing. Multiple potential etiologies for the worsening valve function were noted, and a stepwise iterative optimizing scheme that included basal lateral LV pacing improved mitral valve function and ameliorated heart failure symptoms.     

Animal models of primary myocardial diseases

Feline and canine cardiomyopathies (primary myocardial diseases) were reviewed and divided into three groups based on the clinical, hemodynamic, angiocardiographic, and pathologic findings: (1) feline and canine hypertrophic cardiomyopathy, (2) feline and canine congestive (dilated) cardiomyopathy, and (3) feline restrictive cardiomyopathy. All three groups consisted predominantly of mature adult male cats and dogs. Cardiomyopathy in the hamster and turkey was also reviewed. The most common presenting signs were dyspnea and/or thromboembolism in the cat, systolic murmurs with gallop rhythms on auscultation, cardiomegaly with (groups 1 and 3) or without (group 2) pulmonary edema, abnormal electrocardiograms, elevated left ventricular end-diastolic pressures, and angiocardiographic evidence of mitral regurgitation with left ventricular concentric hypertrophy (group 1), left ventricular dilatation (group 2), or midventricular stenosis (group 3). Some cats in groups 1 and 3 also had evidence of left ventricular outflow obstruction. The principal pathologic findings in all of the cats and dogs were left atrial dilation, hypertrophy, increased septal:left ventricular free wall thickness ratio with disorganization of cardiac muscle cells (group 1); dilatation of the four chambers with degeneration of cardiac muscle cells (group 2); and extensive endocardial fibrosis and adhesion of the left ventricle (group 3). Aortic thromboembolism was commonly observed in the cats of all three groups. These clinical and pathologic findings indicate that cardiomyopathy in the cat or dog is similar to the three forms of cardiomyopathy in humans (hypertrophic, congestive, and restrictive).     

肥厚梗阻性心肌病的外科治疗

目的:总结肥厚室间隔切除术治疗肥厚梗阻性心肌病的手术效果,探讨外科治疗策略。方法:2002年3月至2010年10月,外科手术治疗33例肥厚梗阻性心肌病病人。其中男16例,女17例;年龄13～59岁,平均(42.7±13.6)岁;左室流出道压差(LVOTGP)70～120 mmHg(1 mmHg=0.133Kpa),平均(95.0±22.6)mmHg。其中合并二尖瓣关闭不全24例,主动脉瓣关闭不全7例,升主动脉增宽3例,冠心病2例。手术在全麻低温体外循环下完成,按常规经主动脉切口行室间隔心肌切除术,同期完成二尖瓣置换术(MVR)7例,二尖瓣成形术(MVP)7例,二尖瓣、主动脉瓣成形术(MVP+AVP)5例,二尖瓣、升主动脉成形术3例,二尖瓣、主动脉瓣成形、冠状动脉旁路移植术(MVP+AVP+CABG)2例。分析比较病人术前超声心动图(UCG),术中经食管心脏超声(TEE),以及术后1周、3月、6月、1年超声心动图结果。结果:手术死亡1例(3.0%,1/33例),主要死因为严重低心排综合症以及多脏器功能衰竭。二次开胸止血1例(3.0%,1/33例)。术中经食管心脏超声示所有病人二尖瓣前叶收缩期前向运动现象(SAM征)消失。存活病人手术效果良好,解剖狭窄解除,峰值压差降低,SAM现象基本消失。远期随访生存病人症状消失,生活质量明显改善,心功能I～II级,无远期死亡、并发症或再次手术。结论:外科治疗肥厚梗阻型心肌病具有良好的手术效果。了解病生理过程、术中仔细探察、手术切除彻底是手术成功的关键。     

Right ventricular lead implantation facilitated by a guiding sheath in a patient with severe chamber dilatation with tricuspid regurgitation

Implantation of pacemakers can be challenging in the context of dilated cardiac chambers and valvular regurgitation. We report a difficult case of single chamber pacemaker implantation in a patient with restrictrive cardiomyopathy resulting in grossly enlarged atria and severe tricuspid regurgitation. In this situation, use of a slittable guiding sheath, more typically used for coronary sinus lead implantation, greatly facilitated rapid and stable deployment of the right ventricular lead.     

成人动脉导管未闭合并重度二尖瓣返流的外科治疗

目的:探讨外科手术治疗成人动脉导管未闭(PDA)合并重度二尖瓣返流(MR)的疗效.方法:回顾性分析2009年1月至2011年1月在本中心实施外科手术治疗6例PDA合并MR患者的临床资料.5例实施PDA缝扎术和二尖瓣置换术,1例实施PDA缝扎术和二尖瓣成形术.分别于术前、术后1周、1月、3月和1年行超声心动图检查,观察并测定左室舒张末期内径(LVEDD)和左室射血分数(LVEF)等指标的变化.结果:6例术后PDA均无残余分流.心脏彩超检查显示,术后1周与术前相比,LVEDD显著缩小(P＜0.01),术后1个月较术后1周进一步缩小(P＜0.01),术后3个月与术后1个月比较以及术后1年和术后3月比较LVEDD有所减少,但差异无统计学意义.LVEF术后比术前有所降低,但差异无统计学意义.所有病例在术后随访中未出现栓塞和出血等并发症.结论:外科手术治疗PDA合并MR疗效满意.术前单纯重度MR患者易漏诊PDA,应尽可能明确诊断.     

Visualization of elusive structures using intracardiac echocardiography: Insights from electrophysiology

Echocardiography has the ability to noninvasively explore hemodynamic variables during pharmacologic or exercise stress test in patients with heart failure. In this review, we detail some important potential applications of stress echocardiography in patients with heart failure. In patients with coronary artery disease and chronic LV dysfunction, dobutamine stress echocardiography is able to distinguish between viable and fibrotic tissue to make adequate clinical decisions. Exercise testing, in combination with echocardiographic monitoring, is a method of obtaining accurate information in the assessment of functional capacity and prognosis. Functional mitral regurgitation is a common finding in patients with dilated and ischaemic cardiomyopathy and stress echocardiography in the form of exercise or pharmacologic protocols can be useful to evaluate the behaviour of mitral regurgitation. It is clinical useful to search the presence of contractile reserve in non ischemic dilated cardiomyopathy such as to screen or monitor the presence of latent myocardial dysfunction in patients who had exposure to cardiotoxic agents. Moreover, in patients with suspected diastolic heart failure and normal systolic function, exercise echocardiography could be able to demonstrate the existence of such dysfunction and determine that it is sufficient to limit exercise tolerance. Finally, in the aortic stenosis dobutamine echocardiography can distinguish severe from non-severe stenosis in patients with low transvalvular gradients and depressed left ventricular function.     

Study of the impact of intramyocardial implantation of stem cells on myocardial perfusion and contractility in patients with coronary heart disease concurrent with postinfarct cardiosclerosis and chronic heart failure

OBJECTIVE: to study of intramyocardial implantation of cultured bone marrow stem cells on myocardial perfusion and contractility in the surgical treatment of patients with coronary heart disease (CHD) and chronic heart failure (CHF), by synchronized single-photon emission computed tomography (SSPECT) of the myocardium. SUBJECTS AND METHODS: The study included 11 patients. Intramyocardial injection of cell injections into the myocardial periscarring areas was made at coronary bypass surgery. All the patients underwent 99mTc myocardial SSPECT MIBI before and 3, 6, 12 months after surgery. RESULTS AND CONCLUSIONS: Implantation of bone marrow stem cells into the left ventricular myocardium favorably affects left ventricular remodeling and contributes to the improvement of myocardial perfusion and contractility, as evidenced by 99mTc.     

Moderate ischemic mitral regurgitation (IMR) and metabolic syndrome: where are we now and where are we going?

Background

The metabolic syndrome appears to affect 10% to 25% of adult population worldwide. Several studies have described the association between metabolic syndrome and ischaemic heart disease, however, none linked metabolic syndrome to ischemic mitral regurgitation, a serious clinical problem facing both the cardiologists and cardiac surgeons. Ischemic mitral regurgitation is mitral insufficiency caused by myocardial infarction. The myocardial ischemia can result in altered ventricular geometry, leading to mitral insufficiency. Interestingly metabolic syndrome showed more pronounced alteration of left ventricular geometry and function especially in obese subjects.

Presentation of the hypothesis

We have recently proposed that there is link between metabolic syndrome and ischemic mitral regurgitation and associated complications. Operative strategy for moderate ischaemic mitral regurgitation continues to be debated between revascularisation alone and concomitant valve repair at the time of coronary artery bypass surgery. Each of the above group has published studies, with results supporting each argument.

Testing the hypothesis

Generally speaking the treatments available for metabolic syndrome are based in both life style modification (dietary advice and advice to increase physical activity) and medical treatment to enhance insulin sensitivity. Randomised controlled trials may show whether the current available treatment of metabolic syndrome may have an impact on moderate ischemic mitral regurgitation.

Implications of the hypothesis

Metabolic syndrome was shown to alter left ventricular geometry and therefore it is possible to postulate that the variation in the response of different patients with moderate ischemic mitral regurgitation to current management may be attributed to the absence and presence of metabolic syndrome. Research testing of this hypothesis in the future may reveal whether concomitant treatment of metabolic syndrome will play part in the management of moderate ischemic mitral regurgitation.     

Progressive nature of chronic mitral regurgitation and the role of tissue Doppler-derived indexes

The aim of this study was to determine whether severe mitral regurgitation (MR) is progressive and whether tissue-Doppler (TD)-derived indexes can detect early left ventricular (LV) dysfunction in chronic severe MR. Percutaneous rupture of mitral valve chordae was performed in pigs (n = 8). Before MR (baseline), immediately after MR (post-MR), and at 1 and 3 mo after MR, cardiac function was assessed using conventional and TD-derived indexes. The severity of MR was quantified using regurgitant fraction and effective regurgitant orifice area (EROA). In all animals, MR was severe. On follow-up, the LV dilated progressively over time, but LV ejection fraction did not decrease. With the increase in LV dimensions, the forward stroke volume remained unchanged, but the mitral annular dimensions, EROA, and regurgitant fraction increased (EROA = 41 +/- 2 and 51 +/- 2 mm(2) post-MR and at 3 mo, respectively, P < 0.01). Peak systolic myocardial velocities, strain, and strain rate increased acutely post-MR and remained elevated at 1 mo but declined by 3 mo (anterior strain rate = 2.9 +/- 0.1 and 2.4 +/- 0.2 s(-1) post-MR and at 3 mo, respectively, P < 0.001). Therefore, in a chronic model of MR, serial echocardiography demonstrated that MR begets MR and that those TD-derived indexes that initially increased post-MR decreased to baseline before any changes in LV ejection fraction.     

Beneficial effect of ACE inhibitor in congestive heart failure

The effects of captopril, an angiotensin-converting enzyme inhibitor, on congestive heart failure (CHF) were investigated in animal and clinical studies. Congestive heart failure was induced in rats by a combination of pressure and volume overload. Cardiac pressure overload was induced by constricting one renal artery (Goldblatt rat) and volume overload was induced by aorto-caval fistula. Captopril (100 mg/kg/day) was then administered for 14 weeks. Isometric contraction was assessed using isolated left ventricular papillary muscles. The maximum developed tension and the maximum rate of increase in tension (dT/dtmax) were decreased in untreated rats with CHF and improved in captopriltreated rats. The left ventricular myosin isoenzyme pattern was shifted towards V3 in untreated rats with CHF, and was shifted back towards V1 in the captopril-treated rats. In the clinical study, captopril (37.5–75 mg/day) was administered to patients with cardiomyopathy for 12 months. There was no effect on left ventricular mass in hypertrophic cardiomyopathy, although systolic anterior motion of the mitral valve disappeared in one patient. In dilated cardiomyopathy, however, left ventricular mass tended to decrease. These results indicate that captopril has a beneficial effect in congestive heart failure.     

Intramyocardial and intracoronary autologous bone marrow-derived mesenchymal stromal cell treatment in chronic severe dilated cardiomyopathy

Background aimsMesenchymal stromal cells (MSC) may improve cardiac function following myocardial infarction. MSC can differentiate into cardiomyocytes and endothelial cells while exerting additional paracrine effects. There is limited information regarding the efficacy of route for MSC treatment of severe dilated cardiomyopathy (DCM). The aim of this study was to demonstrate the clinical safety, feasibility and efficacy of direct intramyocardial and intracoronary administration of autologous bone marrow-derived MSC treatment for no-option patients with chronic severe refractory DCM.MethodsTen symptomatic patients with DCM and refractory cardiac function, despite maximum medical therapy, were selected. Five had ischemic DCM deemed unlikely to benefit from revascularization alone and underwent bypass operations with concurrent intramyocardial MSC injection (group A). Two patients had previous revascularization and three had non-ischemic DCM and received intracoronary MSC injection (group B).ResultsGroup A and B patients received 0.5–1.0 × 10⁶ and 2.0–3.0 × 10⁶ MSC/kg body weight, respectively. All patients remained alive at 1 year. There were significant improvements from baseline to 6 and 12 months in left ventricular ejection fraction and other left ventricular parameters. Scar reduction was noted in six patients by 12 months.ConclusionsAutologous bone marrow MSC treatment is safe and feasible for treating chronic severe refractory DCM effectively, via intracoronary or direct intramyocardial administration at prescribed doses.     

Two-dimensional tracking and TDI are consistent methods for evaluating myocardial longitudinal peak strain in left and right ventricle basal segments in athletes

Background

Surgical "anatomical" repair is the most frequent technique used to correct mitral regurgitation due to severe myxomatous valve disease. Debate, however, persists on the efficacy of this technique, as well as on the durability of the repaired valve, and on its functioning and hemodynamics under stress conditions. Thus, a basal and Dobutamine echocardiographic (DSE) study was carried out to evaluate these parameters at mid-term follow-up.

Methods and Results

Twenty patients selected for the study (12 men and 8 women, mean age 60 ± 9 years) underwent pre- and post-operative transthoracic echocardiography (TTE) and intra-operative transesophageal echocardiography (TEE). At mid-term follow-up (20 ± 5 months) all patients underwent rest TTE and DSE (3 min. dose increments up to 40 microg/Kg/min protocol). Pre-discharge and one-month TTE showed absence of MR in 11 pts., trivial or mild MR in 9 pts. and normal mitral valve area and gradients. Mid-term TTE showed decrease in left atrial and ventricular dimension, in pulmonary artery pressure (sPAP) and grade of MR. During DSE a significant increase in mitral valve area, maximum and mean gradients, sPAP, heart rate and cardiac output and a decrease in systolic annular diameter and left ventricular volume were found; in 6 pts. a transient left ventricular outflow tract obstruction was observed.

Conclusion

Basal and Dobutamine stress echocardiography proved to be valuable tools for evaluation of mid-term results of mitral valve repair. In our study population, the surgical technique employed had a favourable impact on several cardiac parameters, evaluated by these methods.     

Heart muscle disease related to HIV infection: prognostic implications.

OBJECTIVES--To determine the natural course of heart muscle disease in patients infected with HIV. DESIGN--Prospective echocardiographic survey and observational study over four years. SETTING--Edinburgh. SUBJECTS--296 adults infected with HIV (mean age 32.7 years (range 21.5 to 67.6) drawn from all the major groups at risk of HIV infection in Britain. MAIN OUTCOME MEASURES--Detection of myocardial dysfunction and time to death from index echocardiogram in serial echocardiography. RESULTS--Cardiac dysfunction was identified in 44 subjects (dilated cardiomyopathy, 13; isolated right ventricular dysfunction, 12; borderline left ventricular dysfunction, 19). Dilated cardiomyopathy was strongly associated with a CD4 cell count of < 100 x 10(6)/l, in contrast with the other forms of cardiac dysfunction. During the study 12/13 (92%) subjects with dilated cardiomyopathy, 5/12 (42%) with right ventricular dysfunction, and 8/19 (42%) with borderline left ventricular function died of conditions related to AIDS. Survival was significantly reduced in the subjects with dilated cardiomyopathy compared with those with normal hearts (P < 0.001). The median survival from the index echocardiogram was 101 days (95% confidence interval 42 to 146) for the subjects with cardiomyopathy compared with 472 days (383 to 560) for those with normal hearts and a CD4 cell count of < 20 x 10(6)/l. No significant difference existed in survival for subjects with borderline left or isolated right ventricular dysfunction. CONCLUSION--Even after adjustment for the significantly reduced CD4 cell count with which dilated cardiomyopathy is associated, the outlook for patients with HIV infection and dilated cardiomyopathy is poor. Isolated right and borderline left ventricular dysfunction are not associated with reduced CD4 cells counts and do not carry adverse prognostic implications.     

Multicenter randomized trial of cell therapy in cardiopathies – MiHeart Study

Background

Cardiovascular diseases are the major cause of death in the world. Current treatments have not been able to reverse this scenario, creating the need for the development of new therapies. Cell therapies have emerged as an alternative for cardiac diseases of distinct causes in experimental animal studies and more recently in clinical trials.

Method/Design

We have designed clinical trials to test for the efficacy of autologous bone marrow derived mononuclear cell therapies in four different cardiopathies: acute and chronic ischemic heart disease, and Chagasic and dilated cardiomyopathy. All trials are multicenter, randomized, double-blind and placebo controlled. In each trial 300 patients will be enrolled and receive optimized therapy for their specific condition. Additionally, half of the patients will receive the autologous bone marrow cells while the other half will receive placebo (saline with 5% autologous serum). For each trial there are specific inclusion and exclusion criteria and the method for cell delivery is intramyocardial for the chronic ischemic heart disease and intracoronary for all others. Primary endpoint for all studies will be the difference in ejection fraction (determined by Simpson's rule) six and twelve months after intervention in relation to the basal ejection fraction. The main hypothesis of this study is that the patients who receive the autologous bone-marrow stem cell implant will have after a 6 month follow-up a mean increase of 5% in absolute left ventricular ejection fraction in comparison with the control group.

Discussion

Many phase I clinical trials using cell therapy for cardiac diseases have already been performed. The few randomized studies have yielded conflicting results, rendering necessary larger well controlled trials to test for efficacy of cell therapies in cardiopathies. The trials registration numbers at the NIH registry are the following: Chagasic cardiomyopathy (NCT00349271), dilated cardiomyopathy (NCT00333827), acute myocardial infarction (NCT00350766) and Chronic Ischemic Heart Disease (NCT00362388).     

A Giant Hydatid Cyst in the Interventricular Septum with Papillary Muscle Involvement

We present here a 44-year-old male patient with hydatid disease who was referred to our hospital due to dyspnea and chest pain for the last 2 month before admission. Using echocardiography and contrast-enhanced computed tomography the heart hydatid was diagnosed. However, hydatid disease of the interventricular septum is rare; particularly, the involvement of mitral apparatus with mitral regurgitation (MR) is an exceptionally rare presentation. Early diagnosis and an integrated treatment strategy are crucial. Surgical excision was performed and the patient had an uneventful recovery and follow-up at 3 months.     

Basal wall hypercontraction of Takotsubo cardiomyopathy in a patient who had been diagnosed with dilated cardiomyopathy: a case report

Background

Takotsubo cardiomyopathy is characterized by the basal hypercontractility and apical ballooning of the left ventriculum and T-wave inversion in the electrocardiogram. It has been suggested that Takotsubo cardiomyopathy might underlie the pathogenesis of persistent cardiac dysfunction; however, few reports are present demonstrating the advent of Takotsubo cardiomyopathy in patients with idiopathic cardiomyopathy.

Case presentation

A 64-year-old women was admitted due to dyspnea on effort and lower extremity edema. She had been diagnosed with idiopathic dilated cardiomyopathy 2.5 years before owing to the reduced left ventricular ejection fraction (24%), normal coronary artery, and interstitial fibrosis of the myocardial samples. On admission, her electrocardiogram showed giant negative T wave in II, III, aVF, and precordial leads. Echocardiography showed dyskinesis of the left ventricular apex and hypercontraction of the basal wall, which had not been observed in the previous examinations. Coronary angiography showed normal coronary arteries, and apical ballooning and basal hypercontractility was confirmed by left ventriculography. On day 15 of admission, contraction of apical wall was recovered, and basal hypercontraction was disappeared.

Conclusion

The present case is the first report demonstrating appearance the transient basal wall hypercontraction along with the advent of Takotsubo cardiomyopathy in a patient diagnosed with dilated cardiomyopathy. Whether such findings are indicative of fair prognosis and have the utility of understanding the pathogenesis of dilated cardiomyopathy needs further investigation.

     

Global longitudinal strain to predict left ventricular dysfunction in asymptomatic patients with severe mitral valve regurgitation: literature review

Netherlands Heart Journal - The optimal treatment strategy for asymptomatic patients with severe mitral valve regurgitation (MR) and preserved left ventricular (LV) function is challenging. This...     

Surgery Issue: Solving the Puzzle of Chronic Ischemic Mitral Regurgitation

Chronic ischemic mitral regurgitation is a prevalent problem among patients following a myocardial infarction. Until recently, the pathophysiology was poorly understood, resulting in surgical strategies with suboptimal results and limited durability. The surgical approach has evolved from revascularization alone to an additional mitral valve procedure, replacement, or repair. When the valve was repaired, isolated annuloplasty was performed. The dilemma that surgeons had when repairing a mitral valve was which type of ring to use and what size. In all series with annuloplasty alone, the results were poor with very high recurrence rates. The primary feature of ischemic mitral regurgitation is a prolapse of the anterior leaflet at A3 ± A2. This prolapse can be caused by fibrotic elongation of the papillary muscle supporting A3 ± A2 or tethering of P3 by a ballooning posterior left ventricular wall. Using a technique that corrects this prolapse with Gore-Tex neochords, we have achieved excellent results with effective and durable correction of the ischemic mitral regurgitation.     

磁共振成像对扩张型心肌病转基因模型小鼠左右心室对比分析

目的对cTnTR141W扩张型心肌病转基因模型小鼠左、右心室进行对比分析,研究cTnTR141W转基因小鼠作为右心室心肌病的动物模型的可行性。方法利用7.0 T高场强磁共振成像(MRI)技术,定量分析了2、4、6和8月龄对照组及cTnTR141W转基因模型小鼠左、右心室的舒张末容积(EDV)、收缩末容积(ESV)和射血分数(EF)的变化情况,同时对6月龄对照组cTnTR141W转基因模型小鼠心肌组织进行组织学分析。结果转基因阴性对照小鼠相比,cTnTR141W转基因小鼠左、右心室的容积在2月龄时已有增大趋势,而射血分数有减小趋势。右心室射血分数减小出现最早也最显著(P<0.05)。随年龄增加,cTnTR141W转基因小鼠与转基因阴性对照小鼠相比,右心室的结构和功能的病理生理变化与左心室同时趋于严重。该小鼠左、右心室在4月龄后表现典型的扩张型心肌病表型。结论 cTnTR141W转基因模型小鼠左心室和右心室的扩张性心肌病表型同时出现,该小鼠可作为右室性心肌病等右心室功能下降相关疾病研究的动物模型。