Current Status of Heart Transplantation and Left Ventricular Assist Device: Major Changes in the Last Decade / 한양의대학술지

Heart transplantation is the last treatment option in refractory end stage heart failure, which can prolong survival. The number of heart transplantations has increased and the survival rate has improved during the last few decades which was contributed by advanced understanding of immunologic mechanism of rejection, pharmaceutical development and clinical management of donors and recipients. However, only a fraction of patients can be offered to transplantation due to shortage of donor heart and many patients suffer high mortality while waiting. Meanwhile, technical advancement of mechanical assist device in recent years enabled long term implantable left ventricular assist devices (LVAD) to bridge the patients with high mortality in the waiting list to transplantation and to assist as a long term destination therapy for patients who are not eligible for transplantation. Development of solid phase assay increased the sensitivity and the specificity of detection of anti-human leukocyte antigen (HLA) antibodies in the recipient. It enabled identifying unacceptable HLA antigens, acquire calculated Panel Reactive Antibodies and perform virtual cross match that can enhance the efficacy of donor allocation system to decrease the waiting time, obviate prospective cross match to decrease ischemic time and to assess the risk of rejection in presensitized patients. Antibody mediated rejection is a challenging entity in diagnosis and management. However, standardized classification of histology and immunology of endomyocardial biopsies was made recently and immunotherapy is moving toward targeted therapies directed at antibody production and function. This review focuses on those major changes in the heart transplantation field in the last decade.

The Brachial Ankle Pulse Wave Velocity is Associated with the Presence of Significant Coronary Artery Disease but Not the Extent

BACKGROUND AND OBJECTIVES: Arterial stiffness is well known as an important risk factor for cardiovascular disease. At our institution, we assessed the association between arterial stiffness, as determined by brachial ankle pulse wave velocity (baPWV), and the extent of coronary artery disease (CAD), as detected by conventional coronary angiography (CAG) in patients who visited the outpatient clinic for angina without any previous history of heart disease. In addition, we evaluated if the level of baPWV could predict the revascularization as a clinical outcome. SUBJECTS AND METHODS: On a retrospective basis, we analyzed the data of 651 consecutive patients who had undergone baPWV and elective CAG for suspected CAD between June 2010 and July 2011, at a single cardiovascular center. RESULTS: The baPWV was one of the statistically meaningful predictors of significant CAD (diameter of stenosis >50%) in addition to male gender, age, the level of high density lipoprotein-cholesterol, and hemoglobin A1c in multivariate analysis. However, baPWV was not the significant predictor of revascularization. When the extent of CAD was classified into following 4 groups; no significant CAD, 1-, 2- and 3-vessel disease, there was significant difference of baPWV between the significant and non-significant CAD group, but there was no difference of baPWV among the 3 significant CAD groups, although there was a trend toward the positive correlation. CONCLUSION: Although baPWV was an independent predictor of significant CAD, it was neither associated significantly with the extent of CAD nor with the risk of revascularization. Therefore, baPWV has a limited value for portending the severity of CAD in patients with chest pain.

A case of papillary fibroelastoma in the left ventricle

Cardiac papillary fibroelastoma (CPF) is a rare and benign primary cardiac neoplasm of unknown prevalence. The incidence of CPF in the left ventricle is lower than that in other parts of the heart. A 65-year-old female was referred to our cardiology department for evaluation of a cardiac mass of the left ventricle. Transthoracic echocardiography revealed a 1.8 x 1.7 cm highly mobile round mass attached by a stalk to the apical inferior wall of the left ventricle with an echolucent area. The mass was successfully removed without any postoperative complications and was identified as a CPF.

Device Closure of a Large Atrial Septal Defect in a Patient with Severe Pulmonary Arterial Hypertension after 1 Year Use of an Oral Endothelin Receptor Antagonist

The presence of severe pulmonary arterial hypertension (PAH) in patients with atrial septal defect (ASD) is still thought to preclude shunt closure, although there are several reports of good clinical outcomes after vasodilator therapy. We report the case of a young woman with ASD and severe PAH who was able to successfully undergo percutaneous shunt closure following 1 year use of the oral endothelin receptor antagonist, bosentan.

Characteristics of QT Dispersion during Recovery Phase after Treadmill Exercise in Airlines Pilots

BACKGROUND: QT dispersion (QTD) represents the inhomogeneity of ventricular repolarization and has been suggested to predict ventricular arrhythmia in patients with coronary artery disease. The purpose of this article is to study the characteristics of QTD during recovery phase after maximal treadmill exercise in airlines pilots. METHODS: The study population included 45 healthy airlines pilots. QTpeak D (QTpD) was defined as the difference between maximum and minimum QTp interval measured on 12 lead ECG at single cardiac beat. Paired t test was used between QTpD at rest and QTpD during recovery phase after maximal treadmill exercise. RESULTS: The QTpD at early recovery phase (1 minute) after maxial treadmill exercise was significantly decreased compared to QTpD at rest (22+/-11 msec. vs 27+/-12 msec., P<0.05), but there was no significant difference between QTpD at rest and QTpD at late recovery phases (3 minutes, 5 minutes and 7 minutes). CONCLUSION: This finding suggests that antiarrhythmogenic effect is present at early recovery phase (1 minute) after maxial treadmill exercise in healthy airlines pilots.

Four Cases of Management of Congenital Coronary Arteriovenous Fistula

Four cases of congenital coronary arteriovenous fistula were diagnosed using coronary angiography. Three cases had fistula-related chest pain and the remaining case showed no symptoms but displayed electrocardiographic changes suggesting myocardial ischemia. As he was elderly and had a potential for future complications, we decided to close the fistulas of all cases. Three cases were closed with transcatheter coil embolization and one with surgical ligation due to a suspicious accompanying pericardial cyst. None of the patients demonstrated periprocedural or perioperative complications and all were relieved from symptoms during the 2 year follow-up period. We concluded that transcatheter coil embolization and surgical ligation are effective methods for use in the management of coronary arteriovenous fistula.

QTp Interval Behavior during Treadmill Exercise in Airlines Pilots

BACKGROUND AND OBJECTIVES: QT interval on ECG strongly depends on heart rate. Prolonged early phase of repolarization may be responsible for mechanisms of arrhythmogenesis. Investigation of physiologic behavior of QT interval and their relation to cardiac cycle length may explain mechanisms of arrhythmogenesis. The aim of this study is to investigate the physiologic behavior of the QT intervals during various stages of treadmill exercise test in healthy airlines pilots. METHOD: A retrospective analysis of treadmill exercise test ws done in 60 healthy men. Each underwent 10 ECG recordings, which were performed in resting, 1 minute, 2 minute and 3 minute of exercise stage 1, 2 and 3 of Bruce protocol respectively. The QT interval was measured as the time interval from the earliest Q onset to the peak T wave (QTp) in precordial lead V2. RESULTS: The mean heart rate before exercise was 72 +/-5 beats/minute, and at 1, 2 and 3 minute of exercise stage 1, 2 and 3 were 96 +/-8, 97 +/-7, 99 +/-9, 112 +/-9, 117 +/-9, 120 +/-10, 137 +/-12, 145 +/-12 and 152 +/-10, respectively. The d-QTp/d-RR at 1, 2 and 3 minute of exercise stage 1, 2 and 3 were 10.4 +/-5.9, 14.1 +/-5.8, 15.1 +/-6.2, 14.8 +/-4.2, 16.1 +/-3.7, 16.3 +/-3.5, 16.8 +/-2.9, 17.1 +/-3.0%, respectively. The QTp interval respond slowly for rapid changes in cycle length. The change of QTp interval showed a linear correlation with the change of the RR interval (y=0.189x-10.864, r=0.83, P<0.0001). CONCLUSION: The changes in QT interval lagged behind the rapid and sustained changes in the heart rate elicited by treadmill exercise test. It is concluded that the d-QTp/d-RR showed hysteresis in the changes in the RR interval may be useful in assessing in the dynamic regulation of the ventricular repolariza-tion process.

Characteristics of QT Interval Dispersion During Exercise-induced Changes of Heart Rate

BACKGROUND: QT interval dispersion (QTD) reflects the regional inhomogeneity of ventricular repolarization, and heart rate variability reflects the autonomic tone of the heart. The relation between QTD and heart rate is not clarified yet. The object of this study was to examine the influence of heart rate on QTD using exercise treadmill test in healthy subjects. METHODS: The influence of heart rate on QTD was studied in 42 young healthy pilots by evaluating the changes in QTD induced by hyperventilation and exercise. QTpeak interval dis-persion (QTp D) was defined as the difference between maximum and minimum QTpeak interval measured on 12 lead ECG at single cardiac beat. Paired t test was used between QTp D at rest, QTp D after hyperventilation and QTp D after exercise to determine the effect of heart rate on QTp D. RESULTS: The QTp D after hyperventilation (37+/-11 msec) was greater compared to QTp D at rest (35 +/-14 msec), but there was no difference (P>0.05). The QTp D after exercise was 31 +/-11 msec at stage 1, 28 +/-13 msec at statge 2 and 31 +/-12 msec at stage 3. and there was the significant difference in QTp D at statge 2 compared to QTp D at rest (P<0.05). CONCLUSION: The QTp D significantly decreased at stage 2 after graded exercise in healthy men. This finding suggests that anti-arrhythmogenic effect associated with decreased QTp D during physiologic exercise is present in apparently healthy men.

Pure Red Cell Aplasia Due to Parvovirus B19 in Renal Transplants / 대한신장학회잡지

Parvovirus B19 infection is known to cause chronic anemia in immunocompromised hosts, including organ transplant recipients. We report a case of pure red cell aplasia caused by parvovirus B19 in renal transplants. The patient was 16-year-old male who was diagnosed as chronic renal failure 7 years ago and had been on hemodialysis twice a week. He got renal transplantation in June 1999. But anemia was not improved in first postoperative period. On admission hemoglobin was 43.0 g/L, hematocrit was 12.7%. The bone marrow biopsy revealed severe erythroid hypoplasia with giant pronormoblasts. The pronormoblasia with giant prominent intranuclear inclusions, characteristic of parvovirus B19 infection. The parvovirus B19 PCR and anti-parvovirus B19 IgM were positive. The patient was treated with intravenous immunoglobulin and then reticulocyte count was increased 5 days later. Hemoglobin level restored to 104 g/L teo months later.

Relationship between ST segment of lateral leads and culprit arteries in acute inferior myocardial infarction

BACKGROUND AND OBJECT: We intended to assess the characteristics of ST segment deviation in lateral leads(aVL, I, V5, V6) in patients with acute inferior myocardial infarction(AIMI) and find out the relationship with culprit arteries. MATERIALS AND METHOD: The subjects were 51 patients diagnosed as AIMI by standard electrocardiogram, cardiac enzymes and typical chest pain. Subjects were devided into two groups by angiographically proven culprit arteries ; left circumflex artery(LCx) group and right coronary artery(RCA) group. We compared the frequencies of ST segment depression more than 1 mm and less than 1 mm in aVL and I, and ST segment elevation more than 0.5 mm and less than 0.5 mm in V5 and V6 in each culprit artery group. RESULTS: Among 51 patients with AIMI, 42 were RCA group and 9 were LCx group. The frequency of ST segment depression more than 1 mm in aVL was 44% in LCx group and 71% in RCA group(p=0.140). 11% of LCx group and 43% of RCA group showed more than 1 mm ST segment depression in lead I (p=0.128). 56% of LCx group showed more than 0.5 mm ST segment elevation in V5 and V6 and 81% of RCA group showed less than 0.5 mm ST segment elevation in V5 and V6 (p=0.036). CONCLUSION: Culprit arteries in patients with AIMI and ST segment deviation in V5 and V6 are significantly related with each other. ST segment elevation more than 0.5 mm in V5 and V6 was predominantly found in LCx group than RCA group. Observation for ST segment deviation in lateral precordial lead V5 and V6 would be important in predicting the culprit artery in AIMI.