2015年 · 第43卷第08期

On the eve of the Spring Festival in 2015, as in previous years, I visited several old leaders and teachers. Every time I meet, I have many things to say. Every time I get the teachings of old leaders and teachers, I benefit a lot.

At 7: 53 a.m. on January 27th, 2015, Mr. Wang Jiarui, a famous expert in cardiovascular medicine, died of illness at the age of 83. An outstanding medical master bid farewell to his beloved medical career forever. We regret and remember the loss of such a medical predecessor infinitely.

Although the implantable cardioverter defibrillator (ICD) and ablation therapy of ventricular tachyarrhythmia have made breakthroughs in recent years, the incidence of sudden cardiac death (SCD) is still increasing worldwide, and it has become a common health problem faced by countries all over the world. As the famous cardiologist DP. Zipes said: Today, the mortality rate associated with ischemic heart disease is decreasing, but the same trend of SCD is not seen. More seriously, most SCD occurs in people with no previous history of heart disease^[1]。

At the beginning of the invention of implantable cardioverter defibrillators (ICD), some scholars even questioned their authenticity. Any progress in science should be recognized with a scientific rigor. At the beginning of ICD clinical application, concerns about the reliability of ICD defibrillation and meticulous and rigorous research are also worthy of recognition. In addition to the stability and reliability of ICD system, the research on defibrillation threshold is the most important. With the development of ICD related technology, how to understand and treat ICD implantation test dynamically and historically is the current concern^[1,2,3,4]。 Combined with the relevant literature, this paper systematically reviews, summarizes and forecasts this problem, and puts forward some views for colleagues' reference.

Hereditary arrhythmias are a large class of primary electrocardiac disorders with autosomal single gene mutation dominant inheritance, mainly including hereditary long QT syndrome (LQTS), catecholamine-sensitive polymorphic ventricular tachycardia (CPVT), Brugada syndrome, short QT syndrome plasma channel disease. Hereditary ventricular arrhythmias have attracted great attention because of their high mortality rate. In recent years, great progress has been made in the genotype and phenotype research of hereditary arrhythmias, and their treatment strategies have also changed significantly. At present, most patients tend to choose drug therapy, especially in economically backward countries and regions. When implantable cardioverter defibrillator (ICD) may not be the first treatment of choice, drug therapy can significantly reduce the symptoms of patients and prolong the life of patients. Among them, the application of β-blockers in hereditary arrhythmias, especially in LQTS and CPVT, is increasingly widespread and gradually mature.

torsades de points (TdP) were first described in 1966 by the French scholar Dessertenne^[1]。 Its electrocardiogram characteristics include: prolonged QT interval of basal rhythm, obvious U wave, ventricular tachycardia (ventricular tachycardia) is often induced by early ventricular diastole after a long interval, heart rate is mostly 160~280 beats/min, QRS wave is wide and deformed, and its amplitude is different. It constantly turns its main wave direction around the baseline, and turns in the reverse direction every 5~20 cardiac cycles. At present, it is believed that its mechanism is related to reentry, which is induced by early and posterior depolarization (EAD) on the basis of the increase of transmural repolarization dispersion (TDR) of myocardium^[2]。 Common causes: Long QT syndrome, severe myocardial ischemia or myocardial disease, use of drugs to prolong myocardial repolarization and electrolyte disorder^{[3,4,5,6,7,8,9]}Decided by themselves and by clinical factors^[10]。 However, there are no relevant reports on its reversal mechanism. Combined with the principle of myocardial electrophysiology and electrocardiogram formation, this paper discusses the possible mechanism of its torsion, deepens the understanding and understanding of this phenomenon, and provides the basis for clinical prevention and treatment.

In the past 20 years, with the continuous progress and deepening of understanding of cardiomyopathy, the definition of cardiomyopathy has been revised many times. In the early stage, it was understood as a myocardial disease related to myocardial dysfunction, and gradually developed to the point where coronary heart disease, hypertension, valvular disease and other causes must be excluded, and then electrocardiac disorder is also covered in the definition^[1]。 Echocardiography, cardiac CT and cardiovascular angiography have certain value in the morphology and function, diagnosis and differential diagnosis of cardiomyopathy. However, the above imaging examinations have certain limitations, such as ionizing radiation, invasiveness and lack of risk prediction. cardiovascular magnetic resonance (CMR) can simultaneously evaluate the anatomical structure, motor function, blood flow perfusion and tissue characteristics of the heart through multi-parameter, multi-plane and multi-sequence imaging. It has unique value in the etiological diagnosis, risk stratification and prognosis judgment of cardiomyopathy, and has become the most ideal non-invasive examination method of cardiomyopathy^[2]。 Although the application of CMR in cardiomyopathy in developed countries is very common, and various new sequence technologies and clinical research results are changing with each passing day, the development of CMR in China is still restricted by many factors such as equipment investment, technical specifications, professional talents and clinical understanding, and has not been widely used yet. In order to give full play to the advantages of CMR and facilitate medical staff to deepen their understanding of new technologies in the field of cardiomyopathy diagnosis and treatment, the Cardiovascular Branch of Chinese Medical Association, the Cardiovascular Physicians Branch of Chinese Medical Doctors Association and the Editorial Committee of Chinese Journal of Cardiovascular Diseases jointly organized and invited clinical experts in cardiovascular and cardiovascular imaging in China to finally complete the first expert consensus on clinical application of CMR in cardiomyopathy in China after preliminary consultation, repeated discussion, joint drafting and many revisions.

The patient, a 23-year-old male, was seen in our hospital on January 12, 2014 due to "repeated dizziness with weakness of both lower limbs for 1 year". Blood pressures of left and right upper limbs were 240/120 and 230/115 mmHg (1 mmHg =0.133 kPa), respectively, and those of left and right lower limbs were 135/80 and 130/85 mmHg, respectively; The breathing sounds of both lungs were coarse, and no dry and wet rales were heard; The boundary of heart turbidity widened to the left, the heart rhythm was uniform, the heart rate was 89 beats/min, and a diastolic rumbling-like murmur could be heard in the auscultation area of mitral valve. Echocardiography showed: left atrial diameter enlarged, left ventricular wall hypertrophy; There was no obvious thickening or calcification of the mitral valve, and a circular fibrous ring was attached to the left atrial side of the valve leaflet, resulting in obvious limitation of valve opening (Figure 1)； Doppler ultrasound revealed an anterior mitral flow velocity of 2.3 m/s. Congenital valve stenosis due to mitral supravalvular annulus is considered. Because of the poor acoustic window of the supraclavian fossa, the multi-slice spiral CT examination of the chest was performed. The results showed that the ascending aorta was widened, and the distal descending aorta of the left subclavian artery was obviously twisted and narrowed (Figure 2)。 Combined with the imaging findings of the patient, the diagnosis was: congenital heart disease: Shone syndrome; Secondary hypertension; Hypertensive crisis. The patient was recommended to go to thoracic and cardiovascular surgery for treatment, but the patient and family members refused. He was given nifedipine controlled-release tablets and irbesartan hydrochlorothiazide to control his blood pressure, and recommended regular follow-up in the outpatient clinic. Two months later, the patient was sent to our hospital due to "sudden loss of consciousness for 10 min". After admission, emergency CT showed massive hemorrhage in the right thalamus, and the hemorrhage broke into the lateral ventricle (Figure 3)。 Physical examination showed a blood pressure of 200/110 mmHg in the right upper limb. Tracheal intubation, ventilator-assisted ventilation, intravenous pumping of sodium nitroprusside, urapidil and other drugs to control blood pressure. Multiple blood biochemical tests after admission showed progressive increases in myocardial necrosis markers, and troponin I was 1.5, 7.9, 13.6 and>30 μ g/L (reference value<0.01 μ g/L). Bedside echocardiography showed that the pulse amplitude of the interventricular septum and left ventricular posterior wall was straight, and the left ventricular ejection fraction was 17%; A cord-like echo was detected in the ascending aorta 5 mm above the aortic valve, which was considered a laceration of the intima aortica. Electrocardiogram showed ST segment elevation in inferior leads. An enhanced CT examination of the chest was performed, and the results showed that the intima of the ascending aorta was completely torn, extending distally to the brachiocephalic trunk and the right common carotid artery (Figure 4)。 Although the patient was actively treated with blood pressure lowering, dehydration, respiratory and circulatory support during hospitalization, his condition did not improve, and he died on the third day after admission.

A 27-year-old pregnant woman was admitted to the hospital on July 3, 2014 due to "33 weeks of menopause and 3 days of vaginal bleeding", and was admitted to the hospital with "33 weeks of menopause threatened premature delivery". Fertility history 0 – 0 – 0 – 0, previous good health, no history of hypertension and other medical conditions. Admission blood pressure 110/78 mmHg (1 mmHg =0.133 kPa). B-mode ultrasound showed intrauterine single fetal cephalic position, fetal heart rate was visible, fetal biparietal diameter was 81 mm, head circumference was 292 mm, amniotic fluid index was 133, and posterior placental wall was grade II. He was given magnesium sulfate, ritodrine hydrochloride and dexamethasone to protect the fetus. In the early morning of July 5th, vaginal fluid and premature rupture of membranes occurred, and a live female baby was delivered naturally at 19:21 on the same day. At 20:07, the patient experienced upper abdominal pain, dyspnea, no dizziness, nausea, vomiting and diarrhea, with a minimum percutaneous oxygen saturation of 94%, and blood pressure measured at that time was 148/88 mmHg. After mask oxygen inhalation, the percutaneous oxygen saturation fluctuated from 94% to 95%, and the blood pressure was 137/86 mmHg. Considering stomach cramps, the effect of giving scopolamine to antispasmodic is not good. On July 6, the patient still complained of upper abdominal discomfort. During the cardiopulmonary auscultation, no obvious abnormalities were found. Serum creatine kinase isoenzyme (CK-MB) was 4.80 μ g/L, N-terminal B-type pronatriuretic peptide (NT-Pro BNP) was 1 839 ng/L, and blood amylase was 160.0 U/L. There were no abnormalities in conventional electrocardiogram and B-mode ultrasound of the upper abdomen. Echocardiography showed mild regurgitation of mitral and tricuspid valves, normal left ventricular function, and no abnormalities of aortic valve, aortic arch and pericardium. Chest enhanced CT showed that the initial part of the descending aorta was widened, and the posterior medial wall dissection was formed. The rupture was located at the initial part of the descending aorta, and the distal end involved the iliac artery branch level. The widest part of the dissection was 17 mm ×37 mm (Figure 1)。 The diagnosis was acute aortic dissection (AAD), Stanford type B. From the first onset of symptoms to the establishment of diagnosis, the delay time was 20 hours. Because of low blood pressure, the heart rate and blood pressure reached the standard after oral administration of metoprolol 25 mg, and was immediately transferred to an external hospital for endovascular isolation of aortic dissection, and the operation was successful.

The patient, a 34-year-old female, was transferred from the obstetrics department of our hospital to the cardiology department on October 4, 2014 due to "intermittent fever for 1 month, 2 days after cesarean section, and 1 day of dyspnea". One month before admission (31 weeks of pregnancy), the patient developed fever without obvious trigger, with a maximum body temperature of 40℃ and dry cough. He went to another hospital, considered pneumonia, and was given anti-infective treatment. He had been given cephalosporin antibiotics and ertapenem successively. Because the patient was worried about adverse effects on the fetus, the medication was irregular. After 3 days of medication, the body temperature dropped to normal and then stopped the medication. However, after 3~5 days, the body temperature rose again, repeatedly, and he still had fever 1 week before admission. Emergency cesarean section due to premature rupture of membranes 2 days before transfer to our department (35 weeks gestation). I had difficulty breathing 1 day before I was transferred to our department, so I could lie down. Past history: 1 child delivered by cesarean section 10 years ago. Since this pregnancy, regular prenatal examination has denied the history of hypertension and diabetes. Deny history of congenital heart disease and other systemic chronic diseases. Deny history of intravenous drug use, deny history of allergies. Physical examination at admission: body temperature 38 ℃, pulse 98 beats/min, breathing 24 beats/min, blood pressure 160/90 mmHg (1 mmHg =0.133 kPa), peripheral blood oxygen saturation 98% (nasal catheter oxygen inhalation 2 L/min). Conscious, full jugular vein. No damage, petechia or ecchymosis were seen on the skin. The breathing sound of both lungs is thick, and the wet rales can be reached in both lower lungs. The heart boundary of percussion is not large, the heart rhythm is uniform, P2 and A2 are roughly equal, and there is no murmur in each valve area. Soft abdomen, no tenderness, unpalpable liver and spleen, negative mobile voicing. Mild concave edema of both lower limbs. Auxiliary examination: blood routine: white blood cells 13.75×10⁹/L, neutrophil percentage 94.4%, hemoglobin 81 g/L, platelets 121×10⁹/L; N-terminal pronatriuretic peptide type B (NT-proBNP): 11 204 ng/L; Liver function: transaminase, total bilirubin and direct bilirubin were normal, albumin 21 g/L; Renal function: urea nitrogen 9.1 mmol/L, creatinine 101 μ mol/L; Urine routine: Protein 3+. Chest radiograph: Scattered patchy exudates on both lungs.

cardiac fibroblasts (CF), cardiomyocytes, endothelial cells and vascular smooth muscle cells are the main cellular components of the heart. Studies have shown that the percentage of fibroblasts in the total number of normal heart tissue cells is closely related to species and developmental stage. The fibroblasts of mice accounted for about 14% of the total number of cardiac tissue cells at 18.5 days of embryonic stage, decreased to 10% at 1 day after birth, and then gradually increased, accounting for about 27% by adulthood. The cardiac fibroblasts of rats accounted for about 30% at 1 d and 64% at 15 d after birth^[1]。 The percentage of human heart fibroblasts has not been reported. CF provides a complete reticular support system for cardiac cell populations by synthesizing and secreting extracellular matrix (ECM) components such as collagen and fibronectin, and plays an important role in maintaining cardiac structure, function, biochemistry and electromechanical signal transduction^[1,2]。