Hypertrophic cardiomyopathy in critical patients

Hypertrophic cardiomyopathy (HCM) is a heterogeneous disease genotypically, phenotypically, pathophysiologically, clinically, and therapeutically. In decisions on the management of these patients, it is important to recognize this heterogeneity and to direct therapy at the predominant abnormalities. The clinical identification and instrumental documentation of cardiac hypertrophy has relevant implications for the prognostic assessment of Intensive Care Unit (ICU) patients, due to the greater risk they face of arrhythmias, sudden death and the tendency of heart failure. In our experience, after heart surgery, a good diagnostic work-up together with tailored treatment are often conducive to stabilization and outcome improvement in the critical patient.     

Intraoperative Management of Liver Transplantation in Patients with Hypertrophic Cardiomyopathy: A Review

Hypertrophic cardiomyopathy (HCM) is a genetic disorder defined by the presence of a hypertrophied nondilated left ventricle in the absence of other known causes. Anatomic variants exist, and dynamic features of this disease process may include left ventricular outflow tract obstruction during systole, systolic anterior motion of the mitral valve, and mitral regurgitation. Patients with HCM are at higher risk for sudden cardiac death, stroke, atrial fibrillation, atrial reentrant tachycardia, syncope, and congestive heart failure (CHF). Few studies have evaluated the perioperative risk of noncardiac surgery in this patient population. However, there appears to be a relatively high incidence of perioperative adverse cardiac events, such as CHF, myocardial ischemia, stable and life-threatening arrhythmias, and transient hypotension. Interoperative challenges of patients with HCM are exacerbated in the setting of end-stage liver disease (ESLD) and liver transplantation. ESLD physiology includes relative hypovolemia, decreased systemic vascular resistance and arterial pressure, and hyperdynamic circulation characterized by increased cardiac output. General anesthesia, release of ascites, temporary occlusion of the inferior vena cava, and reperfusion of the donor liver can result in cardiovascular instability. Liver transplantation is associated with blood loss, hypovolemia, vasodilation, tachycardia, and hypotension. Anesthetic goals to limit the dynamic features of HCM include avoiding tachycardia and increased contractility, as well as maintaining preload and afterload. Transesophageal echocardiography (TEE) is an ideal monitoring technique for patients with HCM undergoing liver transplantation. Benefits of TEE include real-time visualization of cardiac function and structure, better indication of intravascular volume, and immediate evaluation of pharmacologic interventions.     

Hypertrophe Kardiomyopathie

Hypertrophic cardiomyopathy (HCM) is a very heterogeneous disorder with respect to symptoms, phenotype, and genotype. Sudden cardiac death (SCD) can be the first manifestation of HCM. Repeated evaluation of the cardiac phenotype and risk stratification for SCD are essential for optimal patient management. HCM is inherited as an autosomal-dominant trait; at least first-line relatives of index patients should be screened for the presence of HCM. Modern genetic techniques, genotype-phenotype correlation studies, and the analysis of clinical data from informative HCM families will help in the future to better identify HCM patients at high risk of SCD.     

Sudden cardiac death and dialysis patients

Dialysis patients have extraordinarily high mortality rates. The death rate for all US dialysis patients in 2004 was 230 per 1000 patient-years. Cardiac disease is the major cause of death in dialysis patients and accounts for 43% of all-cause mortality. In the United States Renal Data System database 62% of cardiac deaths (or 27% of all deaths) are attributable to arrhythmic mechanisms. The estimated rate of sudden cardiac death in US dialysis patients in 2002 was 7% per year. There are several plausible explanations for the special vulnerability of dialysis patients to sustaining sudden cardiac death. Obstructive coronary artery disease, coupled with diminished tolerance to myocardial ischemia (in the setting of myocardial fibrosis and left ventricular hypertrophy), rapid electrolyte shifts in hemodialysis patients, and derangements in autonomic function may all contribute to this heightened risk of sudden cardiac death. This review focuses on the epidemiology of sudden cardiac death in dialysis patients, underlying mechanisms of sudden death, and potential interventions to reduce the risk of sudden cardiac death in dialysis patients (including medical therapy and defibrillators). It is unlikely that one single therapeutic intervention will prevent sudden cardiac death in dialysis patients; but a more modest (and attainable) goal is the implementation of multiple strategies to reduce the risk of sudden cardiac death in this special high-risk population.     

肥厚型心肌病病人室性心律失常发生率的基因预测

目的 筛选肥厚型心肌病(HCM)高危病人,从而进行重点监护。方法 采用PCR技术对102例HCM病人(观察组)的血管紧张素转换酶(ACE)基因型进行分析,并与98例正常人(对照组)比较,同时比较分析观察组ACE基因型与室性心律失常的关系。结果 两组经电泳得到ACE基因的DD、ID、Ⅱ3种基因图谱,观察组ACE基因DD型及D等位基因频率显著高于正常对照组(均P相似文献   

Perioperative management for patients with hypertrophic cardiomyopathy undergoing noncardiac surgery]

We had two patients with hypertrophic cardiomyopathy for noncardiac surgeries. Case 1: A 74-year-old man for right nephrectomy received epidural lidocaine and nitrous oxide combined with 0.2-0.6% isoflurane. During the operation, heart rate and blood pressure were relatively unstable, but he woke up promptly after the operation. Early on the morning of the 2nd post-operative day, he was found dead on his bed. Case 2: A 52-year-old man for gastrectomy was anesthetized with nitrous oxide and halothane with continuous propranolol infusion. Through the operative period, heart rate and blood pressure were stable and postoperative course was uneventful. In these two patients, preoperative Holter ECG showed ventricular tachycardia, which may increase the risk of a sudden death. These cases demonstrate that general anesthesia with nitrous oxide combined with halothane, can be administered with a low risk in patients with HCM for noncardiac surgery and that postoperative intensive care unit monitoring is necessary for these patients for several days to prevent a sudden death.     

心内科老年患者院内心源性猝死临床病因分析

目的探讨心内科老年患者发生院内心源性猝死的临床原因，便于指导临床干预。方法回顾性分析我院2006年8月～2013年9月心内科住院老年患者48例，分析患者发生心源性猝死的临床病因及时间过程。结果48例心内科老年患者出现院内心源性猝死的临床病因主要有冠心病17例（35．42％）、扩张型心肌病7例（14．58％）、高血压性心脏病6例（12．50％）及风湿性心脏病5例（10．42％）。患者心源性猝死主要发生于病情恶化6h以内，约45例（93．75％）。结论冠心病、扩张型心肌病、高血压性心脏病以及风湿性心脏病患者容易出现院内心源性猝死，患者往往在病情恶化后6h内死亡，需要密切关注该类住院患者的病情进展，并进行有效监护和及时抢救。     

Long‐term support by left ventricular assist device for arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heart muscle disorder characterized by right ventricular enlargement, right heart failure (HF), and ventricular arrhythmias which lead to sudden death especially in young adults. Current recommendations for management of patients with ARVC are antiarrhythmic medications, catheter ablation, and implantable cardioverter defibrillator therapy to prevent sudden cardiac death. However, despite these treatments, few patients suffer from recurrent ventricular arrhythmias or HF unresponsive to conventional management. Heart transplantation (HTx) is a preferred treatment for these cases, but because of a persistent donor heart shortage in Japan, ventricular assist device (VAD) support has become an important option for a management of the end‐stage ARVC. Previous articles reported 4 cases of a successful management by left ventricular assist device (LVAD), but the longest interval of LVAD support was only 333 days. We present 3 cases of ARVC patients who were successfully managed by LVAD implantation for more than a year. These 3 cases are unconventional examples of ARVC patients, considering the nature of the disease. The novelty of these cases should be taken in the context of the extremely long waiting period for HTx in Japan.     

Follow-up of tetralogy of Fallot after repair

Repair of tetralogy of Fallot (TOF) exists for more than 40 years. This repair results in a pulmonary regurgitation, which is usually well tolerated for two decades or so, but eventually this is injurious for the right ventricle (RV). The RV enlargement and severe RV dysfunction increase risk for ventricular tachycardia (VT) and sudden death in the long-term. The pulmonary valve replacement (PVR) is shifting earlier to preserve RV function before patients develop symptoms. Several parameters have to be considered to facilate correct timing for PVR (surgically of by catheterization)?: echocardiography, magnetic resonance imaging, electrocardiogram and cardiopulmonary exercise. All patients should have regular follow-up in a specialized grown-up congenital heart disease (GUCH) center to detect as soon as possible pathological signs of RV enlargement. Implantable cardioverter-defibrillator (ICD) implantation for primary prevention and programmed ventricular stimulation in repaired TOF remain controversal.     

Upper airway obstruction due to inoperable intrathoracic goitre treated by tracheal endoprosthesis.

Thyroidectomy is the treatment of choice in patients with thyroid enlargement complicated by compression or displacement of the trachea because of the risk of complete airway obstruction due to sudden enlargement of the goitre by, for example, haemorrhage. In patients who are medically inoperable an endoscopically inserted tracheal endoprosthesis may provide longstanding airway patency, as reported here.     

Sudden cardiac death and acute myocardial infarction in dialysis patients: perspectives of a cardiologist

Chronic renal failure is characterized by an increased risk for cardiovascular morbidity and mortality, including acute myocardial infarction (AMI). AMI is associated with poor long-term survival in dialysis patients; the 2-year survival rate of 25% has remained unchanged over the past 2 decades. Although underuse of appropriate therapies likely contributes to adverse outcomes, recent data suggest that dialysis patients with AMI are more likely to have clinical presentations atypical for acute coronary syndrome. The risk for cardiac arrest and in-hospital death are increased in dialysis patients with AMI compared with a nondialysis cohort. The phenomenon of increased AMI mortality in patients with chronic kidney disease is not restricted to end-stage renal disease because there is a gradient of mortality risk related to decreased renal function. Sudden cardiac death is the single largest cause of mortality in dialysis patients. Dialysis patients are vulnerable to sudden cardiac death, and myocardial ischemia likely plays a major role. Nevertheless, after percutaneous and surgical coronary revascularization dialysis patients remain at high risk for sudden cardiac death, implying that other factors besides myocardial ischemia are important. A randomized trial testing the efficacy of implantable cardioverter-defibrillators for the prevention of sudden cardiac death in dialysis patients is warranted.     

Modern management of systolic anterior motion of the mitral valve

Systolic anterior motion (SAM) of the mitral valve (MV) can be a life-threatening condition. The SAM can result in severe left ventricular outflow tract obstruction and/or mitral regurgitation and is associated with an up to 20% risk of sudden death (which is substantially lower in hypertrophic cardiomyopathy (HCM)). The mechanisms of SAM are complex and depend on the functional status of the ventricle. The SAM can occur in the normal population, but is typically observed in patients with HCM or following MV repair. Echocardiography (2D, 3D and stress) has a central diagnostic role as the application of echocardiographic SAM predictors allows the incorporation of prevention techniques during surgery and post-operative SAM assessment. Cardiac magnetic resonance imaging has a special role in understanding the dynamic nature of SAM, especially in anatomically atypical hearts (including HCM). This article describes what the clinician needs to know about SAM ranging from pathophysiological mechanisms and imaging modalities to conservative (medical) and surgical approaches and their respective outcomes. A stepwise approach is advocated consisting of medical therapy, followed by aggressive volume loading and beta-adrenoceptor blockade. Surgery is the final option. The correct choice of surgical technique requires an understanding of the anatomical substrate of SAM.     

Cardiovascular Implantable Electronic Device Leads in CKD and ESRD Patients: Review and Recommendations for Practice

Cardiovascular implantable electronic devices (CIEDs) are frequently utilized for management of cardiac dysrhythmias in patients with chronic kidney disease or end‐stage renal disease receiving hemodialysis. The survival benefit from use of implantable cardioverter defibrillators in patients with CKD or ESRD is not as clear as in the general population, particularly when used for primary prevention of sudden cardiac death. Transvenous CIED leads are associated with central vein stenosis resulting in significant adverse consequences for existing or future arteriovenous access. Venous hypertension from CIED lead‐related central vein stenosis is a challenging clinical problem and may require repeated percutaneous interventions, replacement of the CIED, or creation of alternative arteriovenous access. Infections associated with transvenous CIED leads are more frequent and associated with worse outcomes in patients with renal disease. Epicardial CIED leads or other nontransvenous devices may reduce complications of both central venous stenosis and endovascular infection in these vulnerable patients. Consensus recommendations are offered for avoidance and management of complications arising from the use of CIEDs and arteriovenous hemodialysis access.     

Long-Term Outcomes of Orthotopic Heart Transplantation for Hypertrophic Cardiomyopathy

Background

Hypertrophic cardiomyopathy (HCM) is a genetic heart muscle disease characterized by asymmetric or symmetric ventricular hypertrophy in the absence of an obvious clinical cause. Orthotopic heart transplantation (OHT) has been performed in patients who have refractory symptoms despite medical therapy and surgical septal myectomy. However, there is a paucity of data on outcomes of HCM patients who undergo OHT.

Methods

Data on 462 consecutive patients who underwent OHT at UCLA Medical Center from 1996 to 2004 were retrospectively collected. The clinical data on the 11 patients with HCM were identified.

Results

The majority of the HCM patients were male (64%). The mean age of the patient was 45 ± 8 years, and the mean donor age was 35 ± 18 years. The mean ischemia time was 226 ± 60 minutes. There was 1 in-hospital death secondary to septic shock. At a median duration of follow-up of 4.5 years (mean, 4.4 ± 3.2 years), there were 3 additional deaths. Compared with the 451 OHT patients who did not have HCM, there was no difference in survival (P = .13), development of cardiac allograft vasculopathy (P = .46), or rejection (P = .71). There was no evidence of HCM recurrence in biopsies from the donor heart.

Conclusions

OHT is a viable treatment option for patients with end-stage HCM refractory to standard therapies.     

Ventricular late potentials in haemodialysis patients and the risk of sudden death.

Cardiovascular diseases account for approximately 50% of deaths in patients on chronic haemodialysis. Therefore we prospectively studied 54 consecutive patients on dialysis for the presence or absence of ventricular late potentials (LP). LP, i.e. low-amplitude potentials in the terminal part of the QRS complex, have been shown to be highly indicative of life-threatening arrhythmias and sudden death. The results were correlated with echocardiographic studies and the clinical outcome during a follow-up period of 18 months. Fifty patients were suitable for evaluation (29 males, 21 females; mean age 55 years; mean time on dialysis 32 months; coronary artery disease present in 5) Our analysis revealed LP in seven of 50 patients only. Left ventricular hypertrophy, i.e. mean wall diameter > 12 mm, was present in 78%, a compromised left ventricular function, i.e. shortening fraction < 28%, was found in 28% of the patients. With respect to echocardiographic parameters, patients with and without LP were similar. During follow-up, sudden cardiac death was observed in three of 11 patients deceased. LP were detectable in one of the three only. From the remaining six patients with LP, four are still alive, and two patients died due to atherosclerosis and pulmonary embolism. Our data underline the crucial role of sudden cardiac death in dialysis patients. Ventricular late potentials, however, are of no prognostic relevance with respect to identification of dialysis patients at risk of sudden death.     

Anesthesia in a child with newly diagnosed Hypertrophic Cardiomyopathy

We report the initial resuscitation and subsequent management of a child with newly diagnosed Hypertrophic Cardiomyopathy (HCM), which presented as an out of hospital cardiac arrest. HCM is an autosomal dominant condition that is uncommonly encountered in the pediatric setting and is an important cause of sudden death. Here, we describe the safe use of an anesthetic technique for insertion of an implantable cardioverter-defibrillator that ensured strict hemodynamic stability and modest bradycardia.     

Aneurysm enlargement following endovascular aneurysm repair: AneuRx clinical trial

OBJECTIVE: The purpose of this study was to determine the incidence and significance of aneurysm enlargement, with or without treatment, in relation to the primary end points of rupture, surgical conversion, aneurysm-related death, and survival following endovascular repair. METHOD: Aneurysm (AAA) size changes and clinical outcome of all patients treated from 1997 through 1998 during the Phase II AneuRx multicenter clinical trial of endovascular AAA repair were reviewed. Aneurysm dimensions and the presence or absence of endoleak were determined by an independent core laboratory, with enlargement or shrinkage defined as a diameter change of 5 mm or more compared with baseline. RESULTS: Among 383 patients (89% men, 11% women, age 73 +/- 9 years), with a mean device implant time of 36 +/- 11 months (median = 39 months), aneurysm diameter decreased from 5.7 +/- 1.0 at baseline to 5.2 +/- 1.0 at 3 years (P =.0001). A total of 46 patients (12%) experienced AAA enlargement, 199 patients (52%) had no change in AAA diameter, and 138 patients (36%) had a decrease in AAA diameter of 5 mm or more. Significant risk factors for enlargement included age (enlargement patients were 4 years older on average than patients with aneurysms that decreased in size; P =.002) and the presence of an endoleak (P <.001). Among patients with endoleak at any time, 17% had aneurysm enlargement, whereas only 2% of patients without endoleak had aneurysm enlargement (P <.001). Patients with enlargement were more likely to undergo secondary endovascular procedures and surgical conversions (P <.001). Twenty patients (43%) with enlargement underwent treatment, and 26 patients were untreated. There were two deaths following elective surgical conversion and one death in a patient with untreated enlargement and a type I endoleak. Three aneurysms ruptured: one with enlargement, one with no change, and one with a decrease in aneurysm size; all three aneurysms were larger than 6.5 cm. Kaplan-Meier analysis showed that freedom from rupture at 3 years was 98% with enlargement, 99% with no change, and 99% with decrease in AAA size (log-rank test, not significant). Freedom from AAA death at 3 years was 93% in patients with enlargement, 99% in no increase, and 99% in decrease (P =.005). Survival at 3 years was 86% with increase, 82% with no change, and 93% with decrease (P =.02). CONCLUSIONS: Aneurysm enlargement following endovascular repair was not associated with an increased risk of aneurysm rupture or decrease in patient survival during a 3-year observation period. Aneurysm size rather than enlargement may be a more meaningful predictor of rupture. Close follow-up and a high re-intervention rate (43%) may account for the low risk of rupture in patients with enlargement. The long-term significance of aneurysm enlargement following endovascular repair remains to be determined.     

Supracoronary myotomy for myocardial bridges in the setting of hypertrophic cardiomyopathy: off-pump experience

Myocardial bridges (MB) are rarely observed but well known pathology of the major epicardial coronary arteries which are embedded in the overlying myocardial tissue. It is most frequently found in young patients with hypertrophic cardiomyopathy (HCM). Myocardial bridges are associated with myocardial ischemia and infarction, cardiac arrythmias and sudden death. The present case series report the outcomes of three symptomatic patients with hypertrophic cardiomyopathy who underwent myocardial muscle debridges. They were operated using beating heart technique without cardiopulmonary bypass. The authors conclude that off-pump supracoronary muscle myotomy is a feasible treatment modality in the young age group with non-obstuctive hypertrophic cardiomyopathy.     

Sudden death caused by bradycardia and asystole in a heart transplant patient with coronary arteriopathy.

The mechanism of death as a result of allograft ischemic heart disease is not well characterized. Ventricular tachycardia and fibrillation may not be the terminal events they often are in the general population. We report observations in a 41-year-old man with cardiac allograft arteriopathy who died suddenly while wearing an ambulatory monitor. The lethal rhythm was a progressive bradycardia terminating in asystole. Autopsy revealed epicardial and small vessel intramyocardial, coronary arteriopathy, and only mild allograft rejection. It is our belief that ischemia caused the bradycardic sudden death. We would like to hypothesize that prophylactic permanent pacemaker implantation may prevent bradycardic sudden death and improve survival in heart transplant patients with coronary disease.     

When do you implant a pacemaker in myotonic dystrophy?

Myotonic dystrophy is the most frequent adult form of hereditary muscular dystrophy caused by a mutation on the DMPK gene. Myotonic dystrophy leads to multiple systemic complications related to weakness, respiratory failure, cardiac arrhythmias and cardiac conduction disturbances. Age of death is earlier in myotonic dystrophy patients than in general population with a high frequency of sudden death. Several mechanisms are involved in sudden death: atrio-ventricular block, severe ventricular arrhythmias or non-cardiac mechanism. The high degree of atrio-ventricular block is a well-recognized indication of pacemaker implantation but the prophylactic implantation of pacemaker should be considered to prevent sudden death in asymptomatic myotonic dystrophy patients. A careful clinical evaluation needs to be done for the identification of patients at high risk of sudden death. The resting ECG and SA ECG are non-invasive tools useful to select the patients who need an electrophysiologic study. In presence of prolonged HV interval more than or equal to 70 ms one can discuss the implantation of a prophylactic pacemaker. The choice of an implantable cardiac defibrillator is preferred in presence of spontaneous ventricular tachycardia or an alteration of the left ventricular ejection fraction.