Fun-Chung Lin

Lactococcus garvieae infections in humans : possible association with aquaculture outbreaks

Lactococcus garvieae is an important pathogen in aquaculture, outbreaks of which significantly affect production. It is a rare pathogen with a low virulence in human infection. The relation between the aquaculture outbreak and the human infection has not been clarified. Prospective and retrospective epidemiologic surveillance of the four patients with L. garvieae infection between 2000 and 2003 and their relations to the aquaculture outbreaks of L. garvieae were conducted. All the four patients with L. garvieae infection were associated with gastrointestinal disorders. Three of the four patients gave a history of consuming raw fish and in three of the four patients, the infection occurred in summer between June and August while there is a decrease of fisheries production and an increase in L. garvieae infection in aquaculture farms. There was a 100% identity of 16S rDNA sequence of L. garvieae isolates from patient 1 and from the squid muscle obtained from the restaurant where patient 1 consumed the raw fish. Sporadic occurrence of L. garvieae infection in human appears to correlate with the seasonal aquaculture outbreaks of L. garvieae infection. The presence of gastro‐intestinal disorder may facilitate L. garvieae infection.

Enhancement of Quality of Life with Adjustment of Dry Weight by Echocardiographic Measurement of Inferior Vena cava Diameter in Patients Undergoing Chronic Hemodialysis

Background/Aims: Ideal dry weight (DW) can serve as a marker of good quality of life (QOL) in patients receiving chronic hemodialysis. The size of the inferior vena cava (IVC) reflects the intravascular fluid status, and the diameter of IVC correlates indirectly with DW in these patients. Adjusting DW using echocardiographic measurement of the diameter of the IVC thus may be useful in maintenance of a better QOL in patients receiving chronic hemodialysis. Methods: This study included 119 patients with ages ranging between 27 and 90 years (mean ± standard deviation of 58.3 ± 12.8). All of the patients received the IVC diameter (IVCD) measurement by echocardiography every 2 months for 1 year. The study group included 68 patients in whom the DW were adjusted by echocardiographic measurement of the IVCD, while the control group included 51 patients in whom the DW was adjusted by the conventional method. QOL was evaluated using the short form 36 questionnaire (SF-36) at the beginning and at the end of the study. Besides, the Kt/Vurea value, a parameter of total urea clearance, was measured at the beginning and at the end of the study in patients of both groups. Results: The scores of physical functioning, physical role functioning, general health and physical component summary showed a prominent improvement in the study group but not in the control group. The impact of periodic echocardiographic evaluation also demonstrated a significant change in the scores of physical functioning, physical role functioning and physical component summary in the study group. Furthermore, the Kt/Vurea value, a parameter of total urea clearance, also increased significantly in the study group. Conclusion: Ideal DW is better adjusted by periodic echocardiographic measurement of the IVCD in patients undergoing chronic hemodialysis. Maintenance of a better DW leads to improve hemodialysis quality and QOL in these patients.

Mechanisms and clinical significance of transient atrioventricular block during dobutamine stress echocardiography.

OBJECTIVES The purpose of this study was to investigate the possible mechanism and the clinical significance of transient atrioventricular block (AVB) during dobutamine stress echocardiography (DSE). BACKGROUND Transient AVB occurs rarely during DSE; however, the mechanisms responsible for blocks are unclear. METHODS A retrospective analysis of clinical, echocardiographic, catheterization, revascularization and head-up tilting test data was conducted in patients who developed transient AVB during DSE. RESULTS A total of 302 patients with known or suspected coronary artery disease (CAD) underwent DSE before coronary angiography between November 1997 and August 1998. Transient AVB developed in 12 patients during the test. Mobitz I block was noted in six patients and Mobitz II block in the other six patients. Nine of these 12 patients were subsequently shown to have CAD and three had no significant coronary artery stenosis. Mobitz II block was observed only in patients with CAD, while Mobitz I block occurred in three patients with and three patients without CAD (p < 0.05). Eight of the nine patients with CAD underwent a successful coronary angioplasty with or without stenting and a repeat DSE revealed no recurrence of heart block except in one patient. Head-up tilting test in the 12 patients revealed a positive response in three of the nine patients with and all three patients without CAD. A negative head-up tilting test was likely to be observed in patients with, as compared with those without, CAD in this study population (p < 0.05). CONCLUSIONS Transient AVB is not an infrequent manifestation during DSE. Both myocardial ischemia and neurally mediated vagal reflex may be responsible for this phenomenon. The development of Mobitz II block during DSE is indicative of the presence of CAD. A successful revascularization in patients with CAD who develop transient AVB may abolish this phenomenon.

Effects of oral verapamil in patients with atrioventricular reentrant tachycardia incorporating an accessory pathway.

In 14 patients with atrioventricular reentrant tachycardia incorporating an accessory pathway, electrophysiologic studies were performed before and serially at 0.5–1-hour intervals for 6 hours after the fourth dose of 80 mg of oral verapamil given every 6 hours. Verapamil increased both the longest atrial paced cycle length producing type 1 atrioventricular block and the effective refractory period of the atrioventricular conduction system at all measurements. Before verapamil, sustained tachycardia could be induced in all 14 patients. After verapamil, six patients had induction of echo beats alone at all measurements, and in eight patients nonsustained or sustained tachycardia could be induced, particularly after the fourth hour. Follow-up study with oral verapamil at the same dosage in 13 patients for 7 ± 5 months (± SD) revealed that the six patients with induction of echo beats alone have been free of symptomatic arrhythmia, while six of the remaining eight patients had occasional attacks of sustained tachycardia. Thus, oral verapamil increases atrioventricular nodal refractoriness, with an effect lasting up to 6 hours. Electrophysiologic study performed 5–6 hours after verapamil can be used to predict clinical responses in patients with atrioventricular reentrant -tachycardia.

Effects of altered volume loading on left ventricular hemodynamics and diastolic filling during hemodialysis.

Background. Changes in the circulating volume associated with hemodialysis (HD) resulted in alternations of left ventricular (LV) filling. However, previous studies offered conflicting findings. This study thus evaluated the impact of HD on LV diastolic filling indices and hemodynamics. Materials and Methods. Forty patients with end‐stage renal disease were studied by Doppler echocardiography immediately before and after HD. The cardiac size, volume and mass were determined by M‐mode and two‐dimensional echocardiography. LV diastolic filling parameters and hemodynamics were assessed from mitral inflow using Doppler echocardiography. Results. Left atrial and LV dimension, LV volume, and LV mass decreased significantly after HD (p < 0.001). Cardiac output declined from 5.74 ± 1.37 to 4.98 ± 1.27 L/min (p < 0.001), whereas, the ejection fraction remained unchanged. HD elicited marked changes in the early diastolic E (95.1 ± 20.5 to 70.3 ± 18.2 cm/s, p < 0.001) and late atrial filling A velocities (104.3 ± 20.9 to 88.9 ± 16.9 cm/s, p < 0.001). In addition, correction of the deceleration time of E and isovolumic relaxation time prolonged significantly (p = 0.011 and p < 0.001, respectively). Conclusions. Findings in this study indicate that HD altering the loading condition significantly influenced the LV diastolic function and hemodynamics. Moreover, Doppler echocardiography provides an effective means of assessing the effects on LV diastolic filling and hemodynamics during HD.

Variation of P-QRS relation during atrioventricular node reentry tachycardia.

OBJECTIVES The main objective of this study was to characterize the phenomenon of variation in the P-QRS relation during atrioventricular node reentry tachycardia. BACKGROUND Variation of P-QRS relation during tachycardia has been observed occasionally in atrioventricular node reentry tachycardia. However, the incidence, the characteristics and the mechanisms of this phenomenon have not been investigated previously. METHODS Retrospective analysis was performed in 311 consecutive patients with slow-fast form and 108 patients with atypical or multiple form of atrioventricular node reentry tachycardia to examine whether variation of P-QRS relation with changes in AH, HA and AH/HA (A = atria; H = His bundle) ratio occurred during tachycardia. RESULTS A total of 28 patients, 8 with slow-fast and 20 with atypical or multiple tachycardias, were found to manifest this phenomenon. There were 6 males and 22 females, with an average age of 38+/-16 years. In 10 patients, this phenomenon occurred transiently following electrical induction of the tachycardia. In 15 patients, changes in AH, HA and AH/HA ratio were associated with the occurrence of Wenckebach or 2:1 block proximal to the His bundle (H) recording site without interruption of the tachycardia. In nine patients, three with nonsustained tachycardia and six after administration of adenosine triphosphate, this phenomenon was observed at the termination of the tachycardia. This phenomenon was usually accompanied by a mild lengthening of the tachycardia cycle length. CONCLUSIONS Variation of P-QRS relation with or without block may occur during atrioventricular node reentry tachycardia, especially in atypical or multiple-form tachycardias. It was postulated that decremental conduction in the distal common pathway, which exists between the distal link of the reentry circuit and the H, is primarily responsible for this phenomenon.

Metabolic syndrome and homocysteine level as predictors of the severity of coronary artery disease in patients with carotid stenosis.

Background:Coronary artery disease (CAD) is the most important cause of mortality and morbidity in patients who have undergone carotid artery endovascular or surgical intervention. Metabolic syndrome (MetS) and hyperhomocysteinemia (HHCY) have been reported to be associated with CAD. However, no study has investigated the association between MetS or HHCY and the severity of CAD in patients with carotid stenosis. Methods:Total of 148 consecutive patients with at least 1 side of the extracranial internal carotid artery were enrolled. Further, on the basis of the results of coronary angiography, the patients were divided into the CAD group (n = 85) and the non-CAD group (n = 63). Results:Multiple regression analysis revealed that CAD was independently associated with HHCY (odds ratio: 4.07; 95% confidence interval: 1.93–8.57; P < 0.0001) and MetS (odds ratio: 3.38; 95% confidence interval: 1.56–7.29; P = 0.002). Furthermore, multivariate stepwise linear regression revealed that the MetS score and total plasma homocysteine level were significantly correlated with affected vessel number in CAD and the extent of coronary atherosclerosis. Conclusions:MetS and HHCY can predict the presence of CAD in patients with carotid stenosis. Furthermore, the MetS score and total plasma homocysteine level are significantly associated with the extent of coronary atherosclerosis.

Successful lysis of right and left heart thrombus by tissue plasminogen activator.

Tissue plasminogen activator (t‐PA) was administered to three patients with newly developed intracardiac thrombi. Cases 1 and 2 developed right heart thrombi after radiofrequency ablation for atrioventricular nodal reentrant tachycardia and case 3 had tachycardia‐related cardiomyopathy and a left ventricular thrombus. In all three patients, the intracardiac thrombi were successfully eliminated following t‐PA therapy without major bleeding complications. These observations suggest that t‐PA is effective in lysing new thrombus complicating radiofrequency ablation or heart failure and may be the therapy of choice in these conditions. Cathet. Cardiovasc. Intervent. 49:91–96, 2000.

Evaluation of a novel index by tissue Doppler imaging in patients with advanced heart failure: relation to functional class and prognosis

Background:  Despite the ability of tissue Doppler imaging (TDI) to detect left ventricular (LV) systolic and diastolic myocardial functions in patients with heart failure, the added value of TDI to clinical variables and conventional echocardiography in predicting the symptoms and outcome of advanced heart failure has not been clearly defined.

Clinical and Angiographic Outcomes Are Similar with Half, Single, or Multiple Contiguous Palmaz-Schatz Stent Implantations for a Single Coronary Stenosis

We compared the immediate and 6-month clinical and angiographic outcomes in patients undergoing a half, a single, or multiple contiguous stent implantations for a single coronary stenosis. Four hundred forty-three consecutive patients, who underwent elective Palmaz-Schatz stent implantations for 542 stenoses between November 1995 and July 1998, were analyzed. Sixty-three patients with 78 stenoses received a half stent (group A), 346 patients with 395 stenoses received a single stent (group B), and 68 patients with 69 stenoses received multiple overlapping stents (group C) for a single coronary stenosis. Seventy-eight half stents were implanted in 78 stenoses in group A, 395 stents in 395 stenoses in group B, and 141 stents in 69 stenoses in group C. The baseline characteristics were similar in the 3 groups. There were no deaths, no subacute thrombosis, and no vascular complications. Forty-nine patients with 57 stenoses in group A, 280 patients with 326 stenoses in group B, and 59 patients with 60 stenosis in group C underwent 6-month follow-up coronary angiography; the restenotic rate per patient was 10% in group A, 20% in group B, and 24% in group C (NS); the restenotic rate per stenosis was 9% in group A, 18% in group B, and 23% in group C (NS). Follow-up of 18 +/- 3 months revealed no differences in mortality, reinfarction, recurrent angina, target narrowing angioplasty, and elective coronary artery bypass surgery among the 3 groups. The overall cardiac event-free survival was 90%, 82%, and 83% in groups A, B, and C, respectively (p = 0.275). Thus, the procedural success rate, the in-hospital morbidity, and the long-term outcome are similar with coronary stenting using a half, a single, or multiple overlapping Palmaz-Schatz stents for a single stenosis.