Adverse effects of atrial fibrillation and syncope induced by calcium-channel blockers in hypertrophic cardiomyopathy

Calcium-channel blockers are useful for the treatment of hypertrophic cardiomyopathy (HCM), but, their adverse effects, especially, those of diltiazem, have not been of much concern. Forty patients with HCM were treated with calcium-channel blockers such as nifedipine, diltiazem, and verapamil. Atrial fibrillation was induced by diltiazem in two patients and verapamil induced syncope in one patient. The clinical and hemodynamic characteristics of the patients were as follows. All of them had the obstructive type of HCM (HOCM). One of them had a high pressure gradient of the left ventricular outflow tract and the others had earlier onset. In these patients, the left atrial overload seemed to be severe. The vasodilating action of calcium-channel blockers decreases the systemic pressure and in turn, may increase the pressure gradient and the left ventricular end-diastolic pressure. The elevated left ventricular end-diastolic pressure causes the left atrial overload which could be at risk of atrial fibrillation in patients with HCM. Therefore, calcium-channel blockers should be used carefully in peculiar cases of HOCM.     

56例肥厚型心肌病患者的临床分析

目的探讨肥厚型心肌病患者出现晕厥等严重临床症状的预测因素。方法回顾性分析56例肥厚型心肌病患者临床特征,按照有无晕厥的发生进行对照性研究。结果晕厥组中12例QT间期较非晕厥组延长更明显(452±20msvs429±25ms,p<0.01);且晕厥组中病例都出现心尖区3/6级以上收缩期杂音,而非晕厥组中心尖区杂音只有9%(4/44);另外,左室流出道梗阻在晕厥组中亦明显增多(p<0.05)。结论本研究发现对肥厚型心肌病患者发生晕厥等严重临床症状的危险性预测因素有:①QT间期延长;②心尖区3/6级以上收缩期杂音;③左室流出道梗阻。     

Mid‐ventricular obstruction is associated with non‐sustained ventricular tachycardia in patients with hypertrophic obstructive cardiomyopathy

BackgroundMid‐ventricular obstruction (MVO) is a rare subtype of hypertrophic cardiomyopathy (HCM) but it is associated with ventricular arrhythmia. The relationship between MVO and non‐sustained ventricular tachycardia (NSVT) in HCM patients is unknown.HypothesisThe severity of MVO increases the incidence of NSVT in patients with hypertrophic obstructive cardiomyopathy (HOCM).MethodsFive hundred and seventy‐two consecutive patients diagnosed with HOCM in Fuwai Hospital between January 2015 and December 2017 were enrolled in this study. Holter electrocardiographic and clinical parameters were compared between HOCM patients with and without MVO.ResultsSeventy‐six (13.3%) of 572 patients were diagnosed with MVO. Compared to patients without MVO, those with MVO were much younger, and had a higher incidence of syncope, greater left ventricular (LV) posterior wall thickness, a higher percentage of LV late gadolinium enhancement, and higher prevalence of NSVT. Furthermore, the prevalence of NSVT increased with the severity of MVO (without, mild, moderate or severe: 11.1%, 18.2%, 25.6%, respectively, p for trend < .01). Similarly, the prevalence of NSVT differed among patients with isolated LV outflow tract (LVOTO), both MVO and LVOTO, and isolated MVO (11.1%, 21.3%, 26.6%, respectively, p for trend = .018). In addition to age, diabetes, left atrial diameter, and maximal wall thickness, multivariate analysis revealed the presence of MVO as an independent risk factor for NSVT (Odds ratio 2.69; 95% confidence interval 1.41 to 5.13, p = .003).ConclusionsThe presence and severity of MVO was associated with higher incidence of NSVT in HOCM patients.     

Electrocardiography and echocardiography aspects of hypertrophic myocardiopathy in pediatrics

Hypertrophic cardiomyopathy (HCM) is a heterogeneous disease, characterized by asymmetric hypertrophy of the left and/or right ventricle with disarray of myocardial fibers. In order to know its clinical and electrocardiographic manifestation in the pediatric age group, we made a retrospective study of 24 cases from 1986 to 1995. There were: 15 girls and 9 boys, with a mean age of 6 years (age range: 1 month to 17 years). Clinical manifestations were dyspnea (71%), syncope (42%) and palpitations (42%). Physical examination disclosed an aortic systolic murmur in all patients, a mitral regurgitation in 42% and physical signs of congestive heart failure in 54% of patients. Chest X rays showed cardiac enlargement in 71% and pulmonary capillary hypertension in 42%. The most frequent ECG abnormalities were: a prolonged time in the intrinsecoid deflection onset on leads corresponding to the affected region, more or less deep and clean Q waves on leads aVF, aVL, V5 and V6, as well as supraventricular and ventricular rhythm disturbances in 11 patients (46%) with and without congestive heart failure. Bidimensional echocardiography confirmed antero-septal hypertrophy in all patients. The mortality rate was 17%. HCM is rare disease in the pediatric age group. Mortality increases when congestive heart failure and arrhythmias are present. Treatment must be individualized in all cases.     

室间隔介入治疗肥厚型梗阻性心肌病的研究进展

肥厚型心肌病(HCM)是一种并非完全因心脏负荷异常引起的心室壁增厚疾病。尽管HCM是一种常见的心血管疾病,但却缺乏大规模的随机对照临床研究[1]。大约70%的HCM患者存在左室流出道梗阻(LVOTO),LVOTO是决定临床症状,如气短、胸痛、心悸和晕厥的一个重要因素;另外,无论是采取药物治疗还是室间隔切除术或室间隔介入治疗,LVOTO都是长期以来治疗的靶点之一。现将室间隔介入治疗肥厚型梗阻性心肌病(HOCM)的研究进展综述如下。     

高危肥厚型心肌病患者的治疗策略

肥厚型心肌病是以不能解释的左心室肥大为特征、具有常染色体显性遗传特性的心肌疾病。梗阻性肥厚型心肌病患者因左室流出道存在梗阻,故症状明显,且更易出现恶性心律失常或心脏性猝死等严重事件,且尚无理想的治疗措施,目前以药物治疗、室间隔心肌酒精消融术、外科手术为主。现就心率慢而不能耐受药物治疗、具有心脏性猝死家族史且伴有晕厥、恶性心律失常的高危肥厚型心肌病患者的治疗做一综述。     

Right ventricular obstruction in various types of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is most probably a genetically transmitted disease with different clinical and hemodynamic features. In hypertrophic obstructive cardiomyopathy (HOCM) the obstruction is predominantly in the left ventricular outflow tract (IHSS). In a minority of cases the obstruction is strictly located in midventricle (midventricular obstruction, MO). Hypertrophic nonobstructive cardiomyopathy (HNCM) includes asymmetric septal hypertrophy (ASH) and apical hypertrophy (AH). Right ventricular hypertrophic obstruction (RVHO) is an uncommon type of HCM and is almost always combined with other types of left ventricular HCM. We describe in the present report 1 case of RVHO with IHSS, 2 cases with MO and, to our knowledge, the first case with AH.     

肥厚型心肌病患者临床特征及肥厚节段分析

目的 对肥厚型心肌病患者临床特征及其受累肥厚节段的分布和程度进行分析.方法 连续收集2004年3月至2007年3月225例临床诊断或可疑的肥厚型心脏病患者的临床资料,包括症状、体征、心电图检查及超声心动图检查等.所有患者均接受心脏核磁共振检查.依据9节段分析法分析受累节段范围、程度等.结果 肥厚型心肌病患者中男163例,女62例,平均年龄(50.4±14.5)岁.28例肥厚型心肌病患者临床无症状,系通过体检发现.197例肥厚型心肌病患者临床症状明显,其中11例伴发晕厥.216例肥厚型心肌病患者心电图异常,73例患者有明确家族史.126例肥厚型心肌病患者可闻及收缩期杂音.超声心动图发现95例患者合并左心室流出道梗阻,32例患者伴发二尖瓣关闭不全.肥厚型心肌病患者合并高血压50例,合并冠心病14例,合并糖尿病5例.225例患者左心房前后径平均为(39.4±8.3)mm,左心室舒张末期横径平均为(47.8±5.5)mm.依据9节段分析法,32.1%的节段受累.非对称性肥厚患者222例,其中室间隔受累198例,对称性肥厚患者3例.心尖受累67例,其中单独心尖受累24例.98例患者室间隔和左心室前壁同时受累.所有室间隔肥厚患者室间隔平均厚度为(23.0±5.2)mm.其中伴发左心室流出道梗阻患者室间隔平均厚度为(24.3±5.3)mm,高于无梗阻患者(21.6±4.6)mm,P＜0.05.所有心尖肥厚患者心尖平均厚度为(15.6±3.4)mm.结论 我国肥厚型心肌病患者男性比例较高,临床发病时间较晚.心脏磁共振能很好地评估肥厚型心肌病各个亚型的病理解剖学特征,是准确诊断肥厚型心肌病的有效方法.     

Hypertrophic cardiomyopathy complicated by severe bradycardias: a pedigree report

We describe four patients with nonobstructive hypertrophic cardiomyopathy (HCM) from an extended Chinese family. The patients had remarkably similar physical and echocardiographic findings including a harsh localized systolic murmur and apical left ventricular hypertrophy. All four had severe sinus bradycardia and atrial-ventricular conduction block (AVB) manifest by recurrent syncope. Two died suddenly due to bradycardia. Holter monitoring showed no tachycardias. Late potentials were not present. We conclude that this unusual form of HCM may be caused by a new and as yet unknown gene mutation.     

Abnormal QT interval variability in patients with hypertrophic cardiomyopathy: can syncope be predicted?

We sought to determine QT variability pattern in patients with hypertrophic cardiomyopathy (HCM) and its relationship with the risk of syncope. QT interval variability was assessed from 24-hour Holter monitoring in 10 HCM patients with history of syncope, 10 HCM patients without history of syncope, and 10 healthy subjects. QT variability was higher in patients with HCM, in particular in those with history of syncope, than in healthy controls. Time domain QT variability did not vary between waking and sleeping hours in HCM patients, whereas it was significantly shorter while asleep in the control group. Increased QT SDANN identified HCM patients with history of syncope with an accuracy of 75%. Our data show that QT variability is abnormal in HCM patients and indirectly support the concept that arrhythmia-related syncope in these patients may be, at least in part, related to an altered control of repolarization.     

Midventricular obstruction--a form of hypertrophic obstructive cardiomyopathy--and systolic anterior motion of the mitral valve

Hypertrophic cardiomyopathy (HCM) has various manifestations with respect to the localization of the hypertrophy. In this study we report clinical, electrocardiographic (ECG), echocardiographic (echo), and hemodynamic findings in midventricular obstruction (MO), an uncommon form of hypertrophic obstructive cardiomyopathy (HOCM) in 9 patients. The prevalence of systolic anterior motion of anterior mitral leaflet (SAM) in MO, an echocardiographic diagnostic hallmark in HOCM, was another purpose of this study. All patients had complete clinical, ECG, echo, and hemodynamic workup, including left ventricular (in 4 patients simultaneous biventricular, SBVA) and coronary angiograms. All patients had dyspnea and palpitations, chest pain, 2 had syncope. In the ECG, atrial fibrillation was present in 2, and left ventricular hypertrophy in 9 patients. Septal and left ventricular free wall thickening was significantly present in all patients in echo, and SAM in 1 patient. The intraventricular gradient (IVG) was 40-176 mmHg, in 1 case 40 mmHg by provocation, Brockenbrough was positive in all patients. Two patients had right ventricular IVG. A positive beta-blocking agent effect was present in 6 cases. The best localization of the obstruction was possible with SBVA and 2D-echo. We conclude that MO has all the signs of HOCM, but SAM in echocardiography is uncommon. SAM is occasionally present and is not a necessary factor to produce an intraventricular pressure gradient in HOCM, especially in MO. It seems that hypertrophic right ventricular obstruction is relatively common in MO (2 of 9 cases), and may have the same obstructive mechanism.     

Alcohol septal ablation in elderly patients: Is it as effective as in young patients?

Hypertrophic cardiomyopathy (HCM) is a common genetic abnormality that can occur in as many as 1 in 500persons. 1 Researchers have found multiple mutations in 10different sarcomeric proteins such as myosin heavy chain and tropomyosin can cause this disease. ……     

The Frequency and Functional Impact of Overlapping Hypertension on Hypertrophic Cardiomyopathy: A Single-Center Experience

J Clin Hypertens (Greenwich) Between 1995 and 2005, 196 adults with hypertrophic cardiomyopathy (HCM) were evaluated. Among these, 122 (62%, group 1) patients also had systemic hypertension. The clinical presentation, management, outcome, and echocardiographic findings of these patients were compared with 74 (38%, group 2) patients without systemic hypertension. Patients in group 1 were older at the time of HCM diagnosis and had a higher prevalence of diabetes (28% vs 9%; P=.02) and coronary artery disease (40% vs 25%; P=.03). In addition, echocardiography showed a significantly higher prevalence of systolic anterior motion of the anterior mitral valve in association with dynamic left ventricular outflow obstruction (52% vs 19%; P=.02) and mitral annular calcification (27% vs 13%; P=.03) in group 1 patients. Left ventricular wall thickness (17 mm vs 19 mm), end-diastolic diameter (42 mm vs 42 mm), resting outflow tract gradient >30 mm Hg (17% vs 16%), and ejection fraction (65% vs 64%) were similar in the two groups. HCM frequently coexists with systemic hypertension in the adult population. Presence of systemic hypertension in HCM patients is associated with older age and higher risk of diabetes, coronary artery disease, and noncardiac death.     

Acute hemodynamic deterioration during rapid atrial pacing in patients with hypertrophic cardiomyopathy

Background and hypothesis: Supraventricular tachycardia and ventricular tachycardia are often observed in patients with hypertrophic cardiomyopathy (HCM) and they often alter the clinical features of HCM. We examine the influence of supra-ventricular tachycardia on cardiac function and assess the clinical characteristics of patients with HCM. Methods: We studied 32 patients with HCM and 8 normal volunteers using echocardiography under transesophageal rapid atrial pacing. Results: Presyncope-associated hypotension was observed during rapid atrial pacing in 8 HCM patients, but in none of the normal controls. During rapid atrial pacing (144 ± 8 beats/min in HCM, 146 ± 5 beats/min in controls), systolic blood pressure (SBP), the product of left ventricular filling volume (FV) and heart rate, and fractional shortening (%FS) in the HCM patients decreased significantly compared with the basal values (138 ± 19 mmHg vs. 99 ± 24 mmHg, 5.0 ± 1.21/min vs. 2.9 ± 0.91/min, 41.7 ± 6.2 % vs. 35.2 ± 6.0%, respectively), but these decreases were not observed in normal controls. The decrement of SBP during rapid atrial pacing in HCM patients with a history of syncope was more marked than that in those without such history. The decrement correlated positively with the indices of left ventricular hypertrophy (maximal wall thickness and wall thickness index) and with %FS, and correlated negatively with the endsystolic left ventricular diameter at rest. Conclusions: In some patients with HCM, supraventricular tachycardia causes marked hemodynamic deterioration that may be related to a history of syncope, marked hypertrophy, hyperkinesis, small cavity size, and small filling volume of the left ventricle.     

Effect of Cibenzoline,a Class Ia Antiarrhythmic Agent,on Left Ventricular Diastolic Function in Hypertrophic Cardiomyopathy

We aimed to investigate whether the improvement of left ventricular (LV) diastolic function by cibenzoline, a class Ia antiarrhythmic drug, in hypertrophic obstructive cardiomyopathy (HOCM) is due to LV afterload reduction or a primary lusitropic effect on LV. Twenty-three patients with hypertrophic cardiomyopathy (11; HOCM, 12; non-obstructive HCM; HNCM) were examined. Pulsed-wave Doppler, color M-mode and tissue Doppler echocardiography were performed before and 90 minutes after oral administration of cibenzoline (300 mg), and were compared with a treatment of bisoprolol (5 mg/day, 10 days). Early (E) and late diastolic LV inflow velocity, E flow propagation velocity (FPV) and early diastolic mitral annulus velocity (Ea) were measured. E/FPV and E/Ea were calculated as indices of LV filling pressure. LV outflow pressure gradients estimated using continuous-wave Doppler in HOCM markedly decreased after cibenzoline (83 +/- 42 to 40 +/- 33 mmHg, p < 0.005) and bisoprolol (44 +/- 40 mmHg, p < 0.005). Following cibenzoline, E/FPV and E/Ea were significantly decreased in both HOCM (1.75 +/- 0.53 to 1.32 +/- 0.28, p < 0.05, 18.9 +/- 6.2 to 14.8 +/- 5.0, p < 0.05, respectively) and HNCM (1.75 +/- 0.58 to 1.41 +/- 0.73, p< 0.05, 13.0 +/- 4.3 to 9.7 +/- 3.6, p< 0.01, respectively). Those in HNCM did not change by bisoprolol. Cibenzoline improved LV diastolic function in HCM, whereas bisoprolol did not affect it. Thus, the primary lusitropic effect of cibenzoline rather than LV after load reduction might have contributed to the improvement of diastolic function in HOCM.     

Comparison of Modified With Classic Morrow Septal Myectomy in Treating Hypertrophic Obstructive Cardiomyopathy

This study aimed to compare the efficacy and safety of the classic Morrow septal myectomy with the modified procedure in treating hypertrophic obstructive cardiomyopathy (HOCM).A retrospective study was conducted to compare the outcomes of classic with modified Morrow septal myectomy in 42 patients treated from January 2005 to July 2011. Preoperative and postoperative ventricular septal thickness, left ventricular (LV) outflow tract velocity and gradient were measured echocardiographically.In both groups, the ventricular septal thickness, LV outflow tract velocity, and LV outflow tract gradient were significantly decreased after the operation. The modified Morrow procedure group, however, showed significantly greater reduction in these echocardiographic parameters than the classic procedure group. All patients in the modified procedure group were asymptomatic postoperatively with a postoperative transvalvular pressure gradient <30 mm Hg. In the classic procedure group, only 14 (87.5%) patients, however, were asymptomatic postoperatively with a postoperative transvalvular pressure gradient <30 mm Hg, and 2 patients still had severe LV outflow obstruction postoperatively.The modified Morrow septal myectomy is safe and effective in treating HOCM patients, and is superior to the classic procedure in reducing the LV outflow tract gradient and velocity, restoring normal anatomic atrioventricular size, and alleviating symptoms associated with HOCM.     

Hypertrophic Cardiomyopathy

Opinion statement When an individual is diagnosed with hypertrophic cardiomyopathy (HCM), all relatives potentially affected by Mendelian autosomal-dominant inheritance should be evaluated with an electrocardiogram (ECG) and echocardiogram. Genetic testing should be considered in high-risk mutations where there are diagnostic uncertainties. Symptom relief depends on β-blockers as first-line therapy. If the disease is nonobstructive, then calcium channel blockers can be added or used alone. If there is a significant left ventricular outflow tract (LVOT) gradient then disopyramide can be used, ideally in combination with a β-blocker. Verapamil should be used with care due to potential exacerbation of the LVOT gradient. Nonmedical therapy for obstructive disease consists of surgical myectomy, alcohol septal ablation, or dual-chamber pacing. Surgery is the gold standard, although in experienced hands and directed appropriately, septal ablation achieves good results. Pacing is generally less effective. The development of atrial fibrillation (AF) or left atrial enlargement carries a significant risk of thromboembolism. All patients should be closely observed for AF and thromboembolic risk, and the threshold for initiation of anticoagulation should be low in patients with sustained palpitations, atrial enlargement, and nonsustained supraventricular arrhythmia on Holter. All patients with HCM should be assessed for their risk of sudden death regardless of severity of symptoms or morphology. The factors predictive of risk are 1) previous cardiac arrest; 2) unexplained syncope; 3) family history of premature sudden death; 4) abnormal blood pressure response to exercise; 5) nonsustained ventricular tachycardia; and 6) severe left ventricular hypertrophy ≥ 30 mm.     

益气复脉注射液对肥厚型梗阻性心肌病的临床疗效

目的观察益气复脉注射液对肥厚型梗阻性心肌病(HOCM)患者的临床疗效。方法纳入34例HOCM患者,随机分为观察组(n=16)和对照组(n=18例),观察组给予益气复脉注射液治疗,对照组给予灯盏花注射液治疗,疗程为28天。比较两组患者的临床疗效及治疗前、后超声心动图参数变化情况。结果观察组和对照组的临床总有效率分别为:81.3%和27.8%,两组患者治疗后总有效率有显著统计学差异(P0.01)。观察组患者治疗前、后心脏室间隔厚度(VS)、左室后壁厚度(LVPWT)、左室舒张末期内径(LVDED)、左室收缩末期内径(LVSED)、主动脉根部内径(AOD)、左室射血分数(LVEF)、心排出量(CO)水平比较,无统计学差异(P0.05)。观察组患者治疗前、后二尖瓣前叶前向运动分级(SAM分级)、左室流出道(LVOT)流速、二尖瓣舒张期A峰、E峰、左室等容舒张时间(IVRT)、左室舒张高峰充盈率(LVDPFR)、左室舒张高峰充盈时间(LVDPFT)水平比较,有显著统计学差异(P0.05),与对照组上述指标比较亦有统计学差异(P0.05)。对照组患者治疗前后上述指比较,均无无统计学差异(P0.05)。结论益气复脉注射液可改善HOCM舒张功能和降低左室流出道压力阶差,减低左室流出道梗阻,近期疗效满意。     

Noncompaction of Ventricular Myocardium Associated With Hypertrophic Cardiomyopathy and Polycystic Kidney Disease

Noncompaction of ventricular myocardium (NVM), a relatively new diagnostic entity, is described as an arrest in the process of compaction of myocardial fibers, which results in a prominent trabecular network and deep intertrabecular recesses. Its coexistence with other cardiac anomalies like hypertrophic obstructive cardiomyopathy (HOCM) or polycystic kidney disease (PKD) had been reported in the past. We report the first case with all 3 different inherent conditions (NVM, HOCM, and PKD) manifesting in 1 patient. A 37-year-old man was referred for evaluation of a heart murmur. His medical history was positive for paroxysmal atrial fibrillation. Physical examination revealed a grade 3/6 systolic murmur loudest along the left sternal border accentuating on Valsalva maneuver. Echocardiography revealed HOCM. Cardiac magnetic resonance confirmed the presence of HOCM with the incidental finding of NVM and PKD. This case raises the possibility of genetic mutation common to these 3 clinical entities or 2 different gene mutations existing in the same individual.     

Increased intensity of the murmur of hypertrophic obstructive cardiomyopathy with carotid sinus pressure

In a prospective study murmurs increased in intensity with carotid sinus pressure in 18 of 26 patients with hypertrophic obstructive cardiomyopathy (HOCM) (sensitivity, 69.2 percent for the 26 patients, 85.7 percent for the 21 patients in whom heart rate and blood pressure decreased with carotid sinus pressure). On the other hand, the murmur remained constant or decreased in all but one of 104 patients with valvular aortic stenosis, mitral insufficiency, hypertrophic nonobstructive cardiomyopathy, and systolic murmurs of miscellaneous origins (specificity, 99 percent; positive predictive value, 94.7 percent). Catheterization, indirect arterial pressure tracings, and echocardiographic studies indicated that carotid sinus pressure-induced bradycardia was associated with increased left ventricular outflow tract obstruction. The carotid sinus pressure-induced increase in the murmur is probably multifactorial: decreased aortic pressure and impedance; increased contractility immediately on sudden slowing of heart rate; further increase in obstruction as the mitral valve systolic anterior movement is enhanced; and delayed vasodilatation maintaining the obstruction even after return of heart rate to precarotid sinus pressure values. An increase in a systolic murmur with carotid sinus pressure is characteristic of HOCM.