Biomedical subjects

Tsung-Hsien Lin

Publications and source records attributed to Tsung-Hsien Lin.

At least 37 records · Page 2Linked to original sources

PubMed2005

Left ventricular inflow propagation velocity at pulsed wave Doppler analysis: an index of relaxation.

To test whether left ventricular inflow propagation velocity at the pulsed wave Doppler analysis (IPVpw) is a useful noninvasive index of relaxation, 21 patients under coronary angiography for chest pain were included for simultaneous catheter-based and Doppler studies. IPVpw was derived through the application of range ambiguity, and the time constant of isovolumic left ventricular pressure decline (tau) was acquired by a previously described method. At baseline status, IPVpw correlated significantly with the peak negative dP/dt and tau ( r = -0.609, P = .003), but not with the peak velocity of transmitral early flow (E) wave. Sublingual application of nitroglycerin increased heart rate, decreased the transmitral E velocity and transmitral E-to-A velocity ratio, and prolonged the deceleration time of the transmitral E wave. However, there was no significant impact on IPVpw, peak negative dP/dt, or tau. IPVpw correlated with tau ( r = -0.533, P < .001) at the combined analysis of the data before and after nitroglycerin application. In conclusion, IPVpw is a preload-independent, noninvasive index of left ventricular relaxation.

Blood Flow Velocity↗

PubMed2005

Isovolumic relaxation flow propagation velocity in patients with diseases impairing ventricular relaxation.

To evaluate the propagation velocity of isovolumic relaxation flow within the left ventricle (IRFPV) associated with impaired ventricular relaxation, 49 patients with diseases known to impair ventricular relaxation (disease group) and 38 age-matched control subjects (control group) were studied. IRFPV was measured as the slope of the first aliasing velocity line segment of the isovolumic relaxation flow wave front in the color M-mode Doppler echocardiogram. Compared with the control group, the disease group had thicker interventricular septum and left ventricular posterior wall, more left ventricular mass, and lower early diastolic mitral annular velocity (8 +/- 3 vs 11 +/- 4 cm/s, P < .001), early (E) wave propagation velocity (47 +/- 16 vs 70 +/- 41 cm/s, P = .002), and IRFPV (193 +/- 149 vs 395 +/- 220 cm/s, P < .001). No matter in subgroup or whole population analysis, either the early diastolic mitral annular velocity or the E wave propagation velocity was selected as one of the determinants of IRFPV. In conclusion, diseases impairing ventricular relaxation may retard IRFPV.

Aortic Valve Stenosis↗

PubMed2005

Determination of pulmonary capillary wedge pressure using pulsed wave Doppler echocardiography: clinical application of range ambiguity phenomenon.

To predict pulmonary capillary wedge pressure (PCWP) noninvasively, several Doppler combination indices have been developed. Recently, a fair correlation has been found between the time constant of isovolumic left ventricular (LV) relaxation (tau) and pulsed wave Doppler LV inflow propagation velocity (LVIPVpw) derived through the application of range ambiguity phenomenon. In the measurement of LVIPVpw, we can simultaneously measure the peak phantom E-wave velocity (Ep) from the same heartbeat. Hence, it is hypothesized that Ep/LVIPVpw is a useful index in predicting PCWP. In all, 29 patients who underwent elective cardiac catheterization for suggested coronary artery disease were included. Mean PCWP (mPCWP) obtained from right heart catheterization was compared with echocardiographic data before and 5 minutes after sublingual application of nitroglycerin (0.6 mg). Nitroglycerin caused a significant decrease in Ep and mPCWP, but not in LVIPVpw (P < .001, P < .001, and P = .687, respectively). By stepwise multiple linear regression analysis, only the Ep/LVIPVpw (beta = 0.832, P < .001) was the independent predictor of mPCWP. After nitroglycerin intake, the change in mPCWP was significantly correlated with the change in Ep/LVIPVpw (r = 0.455, P = .015). The sensitivity and specificity of Ep/LVIPVpw > 0.74 in predicting mPCWP > 15 mm Hg were 78% and 90%, respectively (area under curve 0.86). In conclusion, Ep/LVIPVpw derived from the same heartbeat provides a good estimate of mPCWP and can be used to rapidly track the change in mPCWP.

Blood Pressure Determination↗

PubMed2005

Tuberculous pericardial abscess: a case report.

We present the case of a 71-year-old diabetic man who came to us complaining of dyspnea for 1 month. Chest X-ray showed cardiomegaly and bilateral pleural effusion. Echocardiography showed a pericardial cystic mass with external compression of the right ventricle. Because of clinically impending cardiac tamponade, we performed urgent sternotomy and removed the pericardial mass without event. Pathologic examination of the excised pericardial specimen showed caseous necrosis compatible with tuberculosis infection. The patient was put on a 1-year treatment regimen of anti-tuberculosis medication. This case is an important reminder that tuberculosis can occur as a pericardial abscess.

Abscess↗

PubMed2005

Flutrer-like P waves in a case of atrioventricular reciprocating tachycardia.

Typical atrial flutter is characterized by its sawtooth flutter wave in leads II, III, aVF, and V1. Atrioventricular reciprocating tachycardia is characterized by its small retrograde P wave after completion of QRS complex, where sawtooth flutter-like P waves are rarely seen in the electrocardiogram during atrioventricular reciprocating tachycardia. We report on a 62-year-old patient who presented the characteristic sawtooth flutter-like P waves in the electrocardiogram during attack of supraventricular tachycardia. By electrophysiologic study, the mechanism of his supraventricular tachycardia was atrioventricular reciprocating tachycardia using the left posterior lateral concealed accessory pathway for retrograde conduction. The accessory pathway was successfully ablated by radiofrequency ablation therapy.

Atrial Flutter↗

PubMed2005

Effects of total coronary artery occlusion on vascular endothieial growth factor and transforming growth factor beta.

Vascular endothelial growth factor (VEGF) and transforming growth factor beta (TGF-beta1) play an important role in angiogenesis. We wanted to determine if concentrations of growth factors in the coronary sinus (CS) and right atrium (RA) are higher in coronary artery disease patients with total occlusions than in those with partial occlusions. Fifty-one patients scheduled for coronary artery angiography were evaluated for possible recruitment. A 6F Goodale-Lubin catheter was used to collect blood from the CS and RA. Data for all but four patients were gathered successfully, leaving 47 study patients. The reviewer was blinded to growth factor data when interpreting coronary angiographic findings. Of the 47 enrolled patients, 32 had at least one diseased vessel, seven of whom had at least one major total epicardial coronary occlusion. In all 32 patients, the concentrations of VEGF in the CS were higher than those in the RA (31.5 +/- 2.7 vs 27.1 +/- 1.8 pg/mL; p = 0.005). Patients with total occlusions had higher VEGF concentrations in the CS than those with non-total occlusions (38.9 +/- 8.0 vs 29.5 +/- 2.6 pg/mL; p = 0.037). The differences in TGF-beta1 in the two groups were not statistically significant. The higher CS VEGF concentrations in patients with total occlusion indicate that VEGF may play a part in the development of angiogenesis.

Aged↗

PubMed2005

Tolerability of ramipril 10 mg daily in high-risk cardiovascular patients in Taiwan: experience from Kaohsiung Medical University Chung-Ho Memorial Hospital.

The Heart Outcomes Prevention Evaluation (HOPE) study demonstrated that the angiotensin-converting enzyme inhibitor, ramipril, significantly reduces mortality, myocardial infarction and stroke in high-risk cardiovascular patients, beyond the benefits from blood pressure lowering. The tolerability of ramipril 10 mg/day has been an important concern when applying these results. Following the same criteria as the HOPE study, we investigated the adverse effects profile and tolerability of 10 mg ramipril in high-risk patients at our institution. In total, 92 patients with high cardiovascular risk were eligible for this study. Initially, ramipril was prescribed 2.5 mg orally once daily, and then titrated up to 5.0, 7.5, and 10.0 mg/day at 1-month intervals. The target maintenance dose was 10 mg/day. All adverse events were recorded during at least 3 months of follow-up. After 4-6 months of the titration protocol, only 18 patients (25.3%) reached and remained on ramipril 10 mg/day; 11 (15.5%), 22 (30.9%), and 20 patients (28.2%) remained on 2.5, 5.0, and 7.5 mg/day, respectively. Twenty-one patients (22.6%) had at least one adverse event. Twelve patients (13.0%) stopped treatment because of adverse effects. A total of 23 episodes of adverse events were reported, including cough (15.1%), dizziness (6.0%), and hypotension (2.4%). Ramipril was relatively well tolerated in our study population. However, only one-quarter of our patients reached the target maintenance dose of 10 mg/day. Dry cough, dizziness, and hypotension were the major side effects. About 15% of our patients discontinued ramipril treatment, which is comparable with previous reports.

Aged↗

PubMed2005

Ruptured aneurysm of the sinus of valsalva into the right atrium without ventricular septal defect: a case report and literature review.

Aneurysm of the sinus of Valsalva (ASV), frequently associated with ventricular septal defect (VSD), is a rare cardiac disease that may be acquired or congenital. Rupture of an ASV, rare in the noncoronary cusp, usually produces serious hemodynamic change and carries poor prognosis if not treated surgically. We present the case of a 55-year-old female who came to us complaining of exertional dyspnea. Transthoracic echocardiography and aortography showed a noncoronary cusp ASV with rupture into the right atrium but without VSD. Because of high left to right shunt flow, she underwent successful surgical intervention with aneurysm repair approached from both the aorta and right atrium with a knitted Dacron patch. This was a rare case of noncoronary cusp involvement in ASV that ruptured into the right atrium without VSD.

Aneurysm, Ruptured↗

PubMed2005

Successful retrieval of dislodged paclitaxel-eluting stent with a nitinol loop snare: a case report.

Coronary stent dislodgment or embolization before deployment is a rare but challenging complication in interventional cardiology. Intracoronary embolization of the dislodged stent is associated with a high risk of coronary occlusion, due to thrombus formation and subsequent myocardial infarction. Furthermore, systemic embolization may cause severe cerebrovascular events. Nonsurgical retrieval strategies for this complication have been suggested, but bailout cardiac surgery may be indicated if percutaneous retrieval attempts fail. To our knowledge, this is the first case report of intracoronary drug-eluting stent dislodgment, and successful retrieval was accomplished by a loop snare technique. With the increasing trend of using drug-eluting stents in percutaneous coronary intervention, the likelihood of stent dislodgment or embolization may increase. It should be kept in mind, especially by coronary interventionists, how to manage this complication.

Angioplasty, Balloon, Coronary↗

PubMed2005

Unstable angina with normal coronary angiography in hyperthyroidism: a case report.

Hyperthyroidism is associated with an increase in myocardial oxygen consumption that, due to an imbalance of oxygen demand and supply, can cause angina. However, subclinical hyperthyroidism rarely presents as chest pain in the resting state. Herein, we present a case of subclinical hyperthyroidism involving a 58-year-old male who complained of frequent chest tightness and typical electrocardiographic changes while in a resting state. Coronary angiography showed no significant lesion. Laboratory data showed that the patient suffered from hyperthyroidism, for which he was successfully treated with anti-thyroid agents. We are reminded that typical chest pain might be the first symptom of hyperthyroidism.

Angina, Unstable↗

PubMed2005

Acute respiratory distress syndrome after early successful primary percutaneous coronary intervention therapy in acute myocardial infarction: a case report.

Acute respiratory distress syndrome (ARDS) is characterized by acute-onset dyspnea, diffuse bilateral pulmonary infiltration, low pulmonary capillary wedge pressure (PCWP), and an arterial oxygen tension/inspired oxygen fraction (PaO2/FiO2) ratio of less than 200 mmHg. Acute myocardial infarction (AMI), whether complicated by circulatory arrest, cardiogenic shock, and hypotension or not, was reported as an etiologic factor in the development of ARDS in the prethrombolytic era. In the thrombolytic era, two cases of AMI complicated with ARDS have been reported. ARDS in these two patients resulted from anaphylactic reaction to the thrombolytic agent and not from the hemodynamic consequences of AMI. Development of ARDS during the AMI period has not been reported after early successful primary percutaneous coronary intervention (PCI). Herein, we report a 61-year-old male patient with persistent chest pain who was diagnosed with Killip II anterior ST-segment elevation AMI. He was treated successfully with primary PCI 2.5 hours after the onset of chest pain. Unfortunately, on the third hospital day, acute-onset dyspnea (respiratory rate, 33 beats/min), fever (38.5 degrees C), leukocytosis (white blood cell count, 18,360/microL), and diffuse bilateral pulmonary infiltration were noted. ARDS was diagnosed from the low PCWP (8 mmHg) and a PaO2/FiO2 of less than 200 mmHg (160 mmHg). No usual causes of ARDS such as infection, aspiration, trauma, shock, or drug reactions were noted. We assumed that, in this particular patient, the systemic inflammatory response syndrome frequently induced by AMI might have caused this episode of ARDS. This may imply that AMI itself is a possible etiology of ARDS.

Angioplasty, Balloon, Coronary↗

PubMed2005

Heparin-induced cardiac tamponade and life-threatening hyperkalema in a patient with chronic hemodialysis.

Heparin, a commonly used anticoagulant agent, is frequently used in patients undergoing hemodialysis. As with most medications, heparin has a significant side effect profile. Two of its most important side effects, major bleeding and hyperkalemia, may be devastating without immediate diagnosis and treatment. Major bleeding such as gastrointestinal, genitourinary or intracranial bleeding is occasionally encountered and rarely neglected. However, heparin-induced cardiac tamponade is rarely encountered and may be easily overlooked. Another side effect, heparin-induced hyperkalemia, an unusual but well-described side effect, is frequently forgotten until life-threatening arrhythmia has occurred. We report a case involving a 40-year-old male patient with uremia, who had received heparin for 10 days for deep vein thrombosis in the left lower extremity. Hemopericardium with cardiac tamponade and life-threatening hyperkalemia were both noted in this patient.

Adult↗

PubMed2005

Vascular endothelial growth factor in coronary sinus: evidence for its association with coronary collaterals.

OBJECTIVES: To explore whether local growth factors concentration, including vascular endothelial growth factor (VEGF) and transforming growth factor beta one (TGF-beta(1)), influence the formation of coronary collaterals. DESIGN: Thirty-six patients scheduled for coronary angiography received a 6F Goodale-Lubin catheterization to collect blood from the coronary sinus (CS) and right atrium (RA). RESULTS: Patients with coronary collaterals had a higher number of diseased vessels (2.6+/-0.2 vs. 1.4+/-0.3, p = 0.005), higher percentage of severity of stenosis (93+/-2 vs. 48+/-8, P < 0.001) and higher VEGF concentrations in CS (38.9+/-3.9 pg/ml vs. 20.8+/-1.4 pg/ml, P < 0.001) and in RA (31.7+/-3.1 pg/ml vs. 22.0+/-2.3 pg/ml, p = 0.004). There was no significant relationship between coronary collateral formation and TGF-beta(1) concentration. By binary logistic regression analysis, VEGF concentrations in CS (p = 0.030) and stenosis severity (p = 0.042) are correlated positively with collateral formation. CONCLUSIONS: The association between local, endogenous secretion of VEGF and coronary collateral formation is compatible with a paracrine role for this growth factor in pathophysiologic collateral formation.

Collateral Circulation↗

PubMed2005

Left ventricular Tei index: comparison between flow and tissue Doppler analyses.

BACKGROUND: It is still unknown whether a correlation exists between left ventricular Tei index obtained by tissue Doppler imaging and that determined by flow Doppler waveforms. This study was conducted to evaluate their relationship and to assess the positional effect on them. METHODS: Twenty-six healthy subjects and 25 patients with essential hypertension were included. On the tissue Doppler images, the time interval from the end to the onset of the mitral annular velocity pattern during diastole and the duration of the S-wave were used to calculate tissue Doppler Tei index. RESULTS: The tissue Doppler Tei index correlated with the flow Doppler Tei index at sitting position (r = 0.406, P = 0.003), but not at left lateral decubitus position. The limits of agreement for the Tei index measured by both methods were -0.26 to 0.62 at left lateral decubitus position and -0.09 to 0.55 at sitting position. Preload reduction associated with sitting position with dangling feet raised the Tei index both in the healthy controls [0.54 (0.14) vs 0.42 (0.12), P < 0.001] and in the hypertensives [0.53 (0.15) vs 0.46 (0.12), P = 0.005]. There was a similar positional effect on the tissue Doppler Tei index in the control subjects [0.75 (0.12) vs 0.53 (0.10), P < 0.001]. CONCLUSIONS: Tissue Doppler Tei index does not seem to be a suitable substitute for flow Doppler Tei index. Flow Doppler Tei index is preload dependent and the loading status should be taken into consideration at the application of Tei index to the evaluation of myocardial performance.

Adult↗

PubMed2005

Morning versus evening administration of a calcium channel blocker in combination therapy for essential hypertension by ambulatory blood pressure monitoring analysis.

Patients with moderate to severe hypertension may need more than two antihypertensive drugs in combination to achieve ideal blood pressure (BP) control. The purpose of this study was to compare the efficacy and safety of administering the antihypertensive agents either all together in the morning or separately with two agents in the morning and one calcium channel blocker (CCB) in the evening. Twenty-four-hour ambulatory BP monitoring (ABPM) was performed among 15 patients (mean, 59 years) with moderate to severe essential hypertension. All patients received at least 3 antihypertensive drugs for ideal BP control. Two treatment regimens were given to each patient: Regimen 1: All antihypertensive agents were given once a day in the morning; Regimen 2: All antihypertensive agents were given in the morning, except the CCB which was given at 4:00 pm. After receiving regimen 1 for 4 weeks, each patient underwent 24-hour ABPM to analyze the BP control. After the first ABPM, each patient was switched to regimen 2. After 4 weeks of treatment with regimen 2, each patient underwent the second ABPM measurement. The pretreatment mean systolic and diastolic BP were 179.6 +/- 21.7 and 107.4 +/- 19.9 mmHg, respectively. Between the two regimens, there was no significant difference in the mean 24-hour BP (126.1 +/- 5.8/73.3 +/- 3.8 versus 130.2 +/- 6.2/75.1 +/- 4.7 mmHg), daytime BP (128.2 +/- 6.5/75.3 +/- 3.8 versus 132.4 +/- 5.8/77.2 +/- 4.4 mmHg), nighttime BP (125.2 +/- 4.9/72.4 +/- 3.3 versus 130.9 +/- 6.2/73.8 +/- 4.1 mmHg), and 24-hour heart rate (65.1 +/- 3.8 versus 64.2 +/- 3.4 bpm). The circadian BP and heart rate profiles were almost identical between regimen 1 and regimen 2. We conclude that in patients with moderate to severe hypertension treated with at least 3 antihypertensive agents, administering a CCB simultaneously with other antihypertensive agents in the morning or separately in the evening did not affect the 24-hour BP control.

Adult↗

PubMed2005

Combined Doppler index to track instantaneous changes in left ventricular filling pressure.

OBJECTIVE: The ratio of early transmitral pulsed Doppler velocity (E) to colour M-mode Doppler flow propagation velocity (Vp) has been reported to be a good predictor of pulmonary capillary wedge pressure (PCWP) and left ventricular end-diastolic pressure (LVEDP). It is unknown whether E/Vp can be used to reflect the instantaneous haemodynamic change after drug intervention. METHODS AND RESULTS: The study population was composed of 19 patients who underwent elective cardiac catheterization for suspected coronary artery disease. Mean PCWP (mPCWP) obtained from right heart catheterization and LVEDP from a micromanometer-tipped catheter were compared with echocardiographic data before and 5 minutes after sublingual application of nitroglycerin (NTG) 0.6 mg. By stepwise multiple linear regression analysis, we found a positive correlation between mPCWP and E/Vp (beta, = 0.687, p = 0.001) and LVEDP and E/Vp (beta, = 0.718, p = 0.001). After NTG intake, the change in ENp was significantly correlated with the changes in mPCWP and LVEDP (r = 0.574, p = 0.010; r = 0.627, p = 0.004, respectively). CONCLUSIONS: In addition to being a useful predictor of mPCWP and LVEDP, the index, E/Vp, can be used to track the instantaneous changes in mPCWP and LVEDRP.

Blood Flow Velocity↗

PubMed2004

Propagation velocity of mitral late flow toward the apex in healthy participants.

The transit time of mitral late flow (A wave) to the outflow tract (A-Ar interval) has been demonstrated to be shorter in the presence of increased ventricular stiffness. However, the A-Ar interval is just a measure of time duration and the data of intraventricular A-wave propagation velocity are still unavailable. In this study we presented the aging trend in various intracardiac Doppler signals, including the mitral A-wave propagation velocity toward the apex (APV(apex)). It was measured as the slope of the first aliasing velocity line segment of the mitral A wavefront at color M-mode Doppler analysis. Age correlated significantly with peak velocity of mitral early flow (E wave), peak A velocity, velocity ratio of E to A wave, deceleration time of E wave, and mitral E-wave propagation velocity toward the apex, but not with the A-Ar interval (r = -0.262, P =.066) or the APV(apex) (r = -0.047, P =.748). Neither the A-Ar interval nor the APV(apex) was different between the young and the elderly groups. Furthermore, there was no significant correlation between the APV(apex) and the A-Ar interval (r = -0.135, P =.348). In conclusion, aging has a major adverse impact on myocardial relaxation associated with a minor one on the noninvasive indices of ventricular compliance. The APV(apex) is age-independent and, moreover, there is no significant correlation between the APV(apex) and the A-Ar interval.

Adult↗

PubMed2004

Ventricular septal rupture after early successful thrombolytic therapy in acute myocardial infarction: a case report.

Ventricular septal defect (VSD) is a severe complication of acute myocardial infarction and has a high mortality rate. This complication appears to have declined in the reperfusion era. It has mostly been reported in elderly or female patients who suffer from anterior wall infarction, patients with multivessel coronary artery disease (CAD) or occluded infarct-related artery (IRA) without collateral circulation, or patients who have had delayed reperfusion therapy. Here, we report the case of a 60-year-old male patient who presented with persistent chest pain and Killip I ST-segment-elevation myocardial infarction. Thrombolytic therapy was started 3 hours after the onset of chest pain. Based on the subsidence of chest pain, resolution of the elevated ST segment, and early peak of cardiac enzymes, reperfusion was thought to be successful. However, on the third day of admission, the patient complained of dyspnea after defecation and was found to have new-onset grade 3 pansystolic murmur over the left sternal border. Cardiac echography showed an apical VSD. A Swan-Ganz catheter was inserted into the right side of the heart; analysis of blood oxygen saturation revealed a 6% step-up of oxygen in the right ventricle. Coronary angiography showed only one-vessel CAD and TIMI 3 flow in the IRA. The patient received intensive medical management and underwent VSD repair and internal mammary artery bypass grafting to the left anterior descending artery. His recovery was uneventful. This case illustrates that VSD can be found in patients receiving early successful reperfusion therapy, with one-vessel CAD, and TIMI 3 flow in the IRA.

Humans↗