Zhongwei Cheng

Danon disease as a cause of concentric left ventricular hypertrophy in patients who underwent endomyocardial biopsy

BACKGROUND Danon disease is an X-linked dominant disorder; concentric left ventricular hypertrophy (LVH) is one of its manifestations. In this study, we investigated the prevalence of Danon disease in patients with concentric LVH who underwent endomyocardial biopsy (EMB). METHODS AND RESULTS A total of 50 patients with concentric LVH underwent EMB from January 2008 to December 2010. Cardiac amyloidosis was diagnosed in 14 patients; genetic analysis of lysosome-associated membrane protein 2 (LAMP2) was done in the remaining 36 patients. Three novel LAMP2 frameshift mutations were found. They were c.808_809 insG in exon 6, c.320_321 insCATC in exon 3, and c.257_258delCC in exon 3, leading to a premature stop codon on cDNA analysis. The prevalence of Danon disease was seen in 6% (3 of 50) of unselected concentric LVH patients who underwent EMB, or 8% (3 of 36) after excluding cardiac amyloidosis through EMB. All the three patients were male teenagers with a mean age of 15 ± 1 years, and had mild mental retardation, two of the three with Wolff-Parkinson-White (WPW) syndrome and markedly increased left ventricular voltage. All the three patients had increased serum hepatic enzymes and creatine kinase (CK) concentrations. There was no death or cardiovascular hospitalization during 20 ± 15 months of follow-up. CONCLUSIONS Danon disease may account for a number of patients with concentric LVH who underwent EMB. Danon disease should be suspected in the male teenager with concentric LVH, especially with elevated serum hepatic enzymes and CK concentrations, and/or WPW syndrome with markedly increased voltage of the left ventricle. Genetic analysis of LAMP2 can help make the diagnosis.

The R-wave deflection interval in lead V3 combining with R-wave amplitude index in lead V1: a new surface ECG algorithm for distinguishing left from right ventricular outflow tract tachycardia origin in patients with transitional lead at V3.

BACKGROUND To distinguish left ventricular outflow tract (LVOT) from right ventricular outflow tract (RVOT) origin in idiopathic premature ventricular contractions or ventricular tachycardia (PVCs/VT) patients with transitional lead at V3 is still a challenge. We sought to develop a new electrocardiography (ECG) algorithm for distinguishing LVOT from RVOT origin in patients with idiopathic outflow tract PVCs/VT with precordial transitional lead at V3. METHODS We analyzed the surface ECG characteristics in a retrospective cohort of idiopathic PVCs/VT patients with transitional lead at V3 who underwent successful radiofrequency catheter ablation and developed a new surface ECG algorithm, then validated it in a prospective cohort. RESULTS A total of 82 consecutive patients (47 ± 17 years, 39% male) underwent radiofrequency catheter ablation of idiopathic outflow tract PVCs/VT between January 2006 and August 2010. Among them, 31 patients (38%) with transitional lead at V3 constituted the retrospective cohort. Based on the areas under the receiver operating characteristic curves, R-wave deflection interval in lead V3>80 ms and R-wave amplitude index in lead V1>0.30 were selected to develop the new surface ECG algorithm. It correctly identified the origin sites of eleven from 12 patients in the prospective cohort, yielding the accuracy of 91.7%. CONCLUSIONS We presented a new simple surface ECG algorithm, R-wave deflection interval in lead V3>80 ms combining with R-wave amplitude index in lead V1>0.30 which can reliably distinguish LVOT from RVOT origin in idiopathic outflow tract PVCs/VT in patients with transitional lead at V3.

The amplitude of fibrillatory waves on leads aVF and V1 predicting the recurrence of persistent atrial fibrillation patients who underwent catheter ablation.

To evaluate whether the amplitude of fibrillatory wave (F wave) on electrocardiography could predict the recurrence in persistent atrial fibrillation (AF) patients who underwent catheter ablation.

Poor prognosis in chronic heart failure patients with reduced ejection fraction in China.

Most Chinese cardiologists are challenged by the high mortality rate of heart failure (HF) in patients with reduced ejection fraction in China. This study was designed as a single-center, retrospective study. All consecutive HF patients with left ventricular ejection fraction (LVEF) ≤ 45% from January 1, 2007, to December 31, 2009, were enrolled. The primary outcome was all-cause mortality. The secondary outcome was all-cause mortality or the first cardiovascular readmission event. A total of 187 patients comprised the study population, classified into two groups: LVEF ≤ 35% (n=83) and LVEF 36% to 45% (n=104). The median follow-up was 18 months (2-41 months). All-cause mortality was 27% among patients with LVEF ≤ 35%, as compared with 14% among those with LVEF 36% to 45% (P=.025). All-cause mortality or first cardiovascular readmission rates were 53% and 32% among patients with LVEF ≤ 35% and 36% to 45% (P=.003), respectively. The predictors of all-cause mortality were advanced age and New York Heart Association functional class, chronic kidney disease, oral β-blockers, and statins at discharge. The prognosis of chronic HF patients with LVEF ≤ 45% was poor in China, especially for patients with LVEF ≤ 35%. Cardiologists should provide further efforts to improve the prognosis of HF in Chinese patients.

Electron microscopy in patients with clinically suspected of cardiac amyloidosis who underwent endomyocardial biopsy and negative Congo red staining

We read with great interest the article by Zuchi et al. about microvascular angina in women [1]. The authors make a very interesting review, however, wewould like to point out an important aspect about of the dynamic evaluation of patients with microvascular angina and the test of ergospirometry, a diagnostic tool which from our point of view, should not be forgotten [2–4]. Cardiopulmonary exercise testing (CPET) is an important diagnostic modality in the clinical assessment of patients with heart failure. Its potential utility in defining physiologic abnormalities in other patient populations has recently garnered attention [5]. The use of ventilatory expired gas analysis for patients undergoing exercise testing for suspected myocardial ischemia is not a commonplace in the clinical setting at this time. In recent years, however, several investigations have demonstrated the potential utility of CPET in this setting [6–8]. The microvascular coronary disease directly affects the oxygen supply to the working muscle because it is mostly dependent on coronary flow compared with an arteriovenous oxygen difference in the heart, which is markedly different from the peripheral muscle [9]. It means that when the extractable oxygen flow falls below demand, either metabolic change will soon follow or lipid predominance in producing adenosine triphosphate shifts to glucose dependence in the ischemic cardiac muscle, after adenosine triphosphate depletion above the point of aerobic oxidation. Thus, functional derangement and recovery related to ischemia depend on myocardial oxidative metabolism [9]. This metabolic failure is followed by contraction failure, increased filling pressure, electrocardiographic changes and angina (Fig. 1). Recent studies have found that the real-time change in the oxygen pulse and change in oxygen consumption/change in Wattss trajectories are most valuable when using CPET to assess for exercise-induced myocardial ischemia.Under normal physiologic conditions, both of these relationships progressively rise during maximal exercise testing. However, left ventricular dysfunction induced bymyocardial ischemia causes both the oxygen pulse and change in oxygen consumption/change in Wattss trajectories to prematurely flatten or decline [5]. Peix et al. have demonstrated that women diagnosed of microvascular ischemia, frequently developed left ventricular dysfunction during exercise testing [10]. CPET may be of diagnostic value to reduce the high rate of false positive stress electrocardiogram tests observed in women. More investigations should be directed at thoroughly evaluating the role of CPET in the diagnosis and assessment of microvascular ischemia. Therefore, in this review, the omission of this technique could deprive at the medical community of potentially useful information. The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology.

Coronary angiographic features of cardiac pheochromocytoma

a Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China b Department of Cardiac surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China c Department of Endocrinology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China