Comparison of vectorcardiographic and 12-lead electrocardiographic detections of abnormalities in repolarization properties due to preexcitation in patients with Wolff-Parkinson-White syndrome: proposal of a novel concept of a "remodeling gradient"

Repolarization abnormalities after radiofrequency ablation in patients with manifest Wolff-Parkinson-White syndrome (WPW) have been attributed to cardiac memory of pre-existing changes in repolarization properties. We compared spatial ventricular gradient (VG) from vectorcardiograms with QRST values of 12-lead ECG in 41 patients with WPW (group A, manifest WPW due to left-sided accessory pathway (n = 20); group B, manifest WPW due to right-sided accessory pathway (n = 12); group C, concealed WPW (n = 9)) before and after ablation. Group N (n = 607) served as control. In groups A and B, the abnormalities of spatial VG and QRST values of 12-lead ECG that existed before and 1 day after ablation significantly decreased 1 week after ablation. In group C, spatial VG and QRST values of 12-lead ECG showed no significant changes. The diagnostic ability of spatial VG is almost equivalent to that of the QRST value of ECG in detecting repolarization abnormalities in patients with WPW before and after ablation. We propose a new concept of a "remodeling gradient" directing from the preexcited area to the opposite side of the ventricle as a result of preexcitation-induced electrical remodeling.     

Assessment of autonomic nervous system modulation after novel catheter ablation techniques for atrial fibrillation using multiple short-term electrocardiogram recordings

Purpose

The effect of novel catheter ablation techniques for atrial fibrillation (AF) on the autonomic nervous system (ANS) is unclear. This study aimed to assess the ANS after three novel catheter ablation techniques for paroxysmal AF by evaluating heart rate variability (HRV) parameters using a 3-min electrocardiogram recording.

Methods

Two hundred and thirty-five patients who underwent catheter ablation for paroxysmal AF (119 in irrigated-tip, 51 in contact-force sensing-guided, and 65 patients in second-generation cryoballoon ablation) were included. HRV analysis was performed at baseline and 1, 3, 6, and 12 months after the ablation.

Results

The three ablation groups had similarly decreased HRV parameters after the ablation, and this change was maintained > 1 year. A reduction in parasympathetic nervous function was more apparent after the ablation, compared to changes in the sympathetic nervous function. Of the total population, 45 patients had recurrence. Ln high frequency (HF) 12 months after the ablation was significantly higher in the recurrence group than in the non-recurrence group (1.52 ± 0.47 vs. 1.26 ± 0.57 ms², p = 0.007). Multivariate analysis demonstrated that AF duration (hazards ratio 1.09, 95% confidence interval 1.04–1.15, p = 0.001) and ln HF 12 months after ablation (hazards ratio 1.91, 95% confidence interval 1.12–3.25, p = 0.017) were independent predictors of AF recurrence after the ablation.

Conclusions

ANS modulation after the three catheter ablation methods was similar and maintained > 1 year after the procedure. Higher parasympathetic nervous function at 1 year after ablation was associated with AF recurrence after the ablation.

     

Application of thrombin-antithrombin III complex for detecting a latent hypercoagulable state in patients with coronary artery disease

It is thought that a hypercoagulable state contributes to the pathogenesis of coronary artery disease (CAD), but few sensitive markers have been available for detecting the state. In the present study the plasma level of thrombin-antithrombin III complex (TAT), a specific indicator of thrombin generation in blood, was investigated before and after a submaximal exercise test in 18 patients with CAD and in 12 healthy controls. The mean (+/- SEM) value of plasma TAT before the exercise was 3.30 (0.81) ng/ml in the patient group and 1.49 (0.08) ng/ml in controls, and its level increased to 29.22 (5.74) ng/ml and 12.07 (2.89) ng/ml after the exercise, respectively. Thus, the TAT value in the patient group was higher than that in the controls both before and after the exercise. However, no differences could be found between the groups in the following parameters; prothrombin time, activated partial thromboplastin time, antithrombin III, fibrinogen, FDP, plasminogen, alpha 2-plasmin inhibitor, and alpha 2-macroglobulin. Through these results it was concluded that plasma TAT level could be a sensitive marker for latent activation of blood coagulation, and also that the results of these experiments showed that patients with CAD were in a latent hypercoagulable state.     

Impedance cardiography for cardiac output estimation: reliability of wrist-to-ankle electrode configuration.

BACKGROUND: Non-invasive measurement of cardiac output (CO) may become an important modality for the treatment of heart failure. Among the several methods proposed, impedance cardiography (ICG) has gained particular attention. There are 2 basic technologies of ICG: thoracic and whole-body ICG whereby the electrodes are applied either to the chest or to the limbs. The present study is aimed to test the effectiveness of the Non-Invasive Cardiac System (NICaS), a new ICG device working with a wrist-to-ankle configuration. METHODS AND RESULTS: To evaluate the reliability of NICaS derived CO (NI-CO), 50 CO measurements were taken simultaneously with thermodilution (TD-CO) and modified Fick (Fick-CO) in 35 cardiac patients, with the TD-CO serving as the gold-standard for the evaluation. Overall, 2-tailed Pearson's correlation and Bland-Altman limits of agreement between NI-CO and TD-CO were r=0.91 and -1.06 and 0.68 L/min and between Fick-CO and TD-CO, r=0.80 and -1.52 and 0.88 L/min, respectively. Good correlation was observed in patients with loading conditions altered by nitroglycerin and also in patients with moderate valvular diseases. CONCLUSION: Agreement between NI-CO and TD-CO is within the boundaries of the FDA guidelines of bio-equivalence. NI-CO is applicable for non-invasive assessment of cardiac function.     

Advanced age is not correlated with either short-term or long-term postoperative results in lung cancer patients in good clinical condition

OBJECTIVES: Several investigators have reported that operative mortality in the elderly is acceptable. However, their patients are potentially biased with regard to some factors such as performance status (PS) and comorbidity. In this study, we discuss surgical indications for the elderly and effects on perioperative mortality and prognosis. STUDY DESIGN: A retrospective study was carried out by reviewing the records of 1,114 patients who were referred for treatment of non-small cell lung cancer between January 1993 and December 2002. The patients were classified into younger (< or = 75 years of age) and elderly (> or = 76 years of age) groups. The histologic subtype, TNM stage, Eastern Cooperative Oncology Group PS, and treatment were reviewed for members of each group, and the proportion of patients who underwent surgery was compared between the two groups. The surgical procedures, perioperative mortality, and prognosis of the two groups were also compared. RESULTS: There was a significant difference in the histologic distribution with no difference in TNM staging between the two groups. Regarding treatment, 51.0% of those in the younger group and 36.1% of those in the elderly group underwent surgery. The proportion of elderly patients who underwent surgery was significantly lower than that of the younger patients, mainly due to worse PS and comorbidity in the elderly patients. The perioperative mortality rates for the younger and elderly groups were 0.9% and 4.1%, respectively, with no significant difference, and the overall survival was similar between the two groups. CONCLUSIONS: When compared to younger patients, fewer elderly patients underwent surgery because of worse PS and comorbidity. However, in elderly patients with good PS and no comorbidity, the rate of perioperative mortality and the prognosis were similar to those in the younger patients. Therefore, advanced age only is not a negative factor for surgery in elderly patients.     

Evaluation of prophylactic use of lamivudine in HBV-positive patients with malignant lymphoma undergoing chemotherapy

A prospective evaluation was carried out on the effect of lamivudine administration as a prophylactic measure to prevent exacerbation of hepatitis in HBV carrier or chronic hepatitis B patients with malignant lymphoma undergoing chemotherapy. Eighteen patients were registered between 1997 and 2002 from institutions of the Research Group for the Treatment of Malignant Lymphoma. The patients' median age was 53 years old (39-73), and consisted of 8 males and 10 females. HBe-seroconversion had already occurred in 13 and liver biopsy had been performed in 8. No adverse effects of lamivudine were noted and the serum HBV-DNA content did not increase during lamivudine administration. Planned treatment courses could be completed in all patients. In 2, however, the viral load increased and the HBe antibody (Ab) value declined after the cessation of lamivudine, which were reversed to the normal ranges following the resumption of lamivudine. As for the overall outcome, 14 of the patients survived, and there were 4 fatalities due to malignant lymphoma. Serum HBeAb status may be regarded as a useful laboratory marker for deciding the safe cessation of lamivudine. An additional case is described, who had recovered from past HBV infection, but eventually succumbed to fulminant hepatitis after the cessation of lamivudine covering prolonged courses of chemotherapy. This illustrates a need for inclusion of such cases for the prophylactic use of lamivudine.     

Magnetic resonance imaging differentiated partial from complete absence of the left pericardium in a case of leftward displacement of the heart.

A 44-year-old man was referred to hospital for the evaluation of atypical chest pain. His chest X-ray showed leftward displacement of the heart. During echocardiography, the apical window displaced laterally in the usual left lateral position and characteristic motions of the interventricular septum and left ventricular posterior wall were recognized with postural alterations. We presumed a complete absence of the left pericardium. Magnetic resonance imaging (MRI), however, demonstrated a partial left-sided pericardium. The diagnosis was corrected to partial absence of the left pericardium and we have carefully followed up this case without surgical prophylactic intervention. It is very important to differentiate partial from complete absence of the pericardium, because only in patients with partial absence of the pericardium is there a risk of fatal myocardial strangulation. The features of the chest X-ray and echocardiography of this case, which strongly suggested complete absence of the left pericardium, are possibly not always reliable signs. In cases with these abnormal imaging features, MRI may provide additional useful information, as in this case.     

Paraneoplastic neurological syndrome accompanied by severe central hypoventilation and expression of anti-Hu antibody in a patient with small cell lung cancer]

A 65-year-old man was admitted to our hospital complaining of diplopia, dysarthria, difficulty in walking and progressive dysesthesia that developed in his left hand and leg. Brain MRI revealed high signal intensity regions on T2-weighted and FLAIR images of the hippocampus and the corpus amygdaloideum. After admission, the patient's neurological symptoms progressed to delirium and dementia with hallucinations. When he eventually developed severe respiratory failure requiring ventilatory support, brain MRI revealed new high signal intensity regions on T2-weighted images of the medulla oblongata and pons. Chest CT scans showed a mass under the aortic arch, and based on subsequent histopathological examination of a transesophageal endoscopic ultrasonography-guided fine needle aspiration biopsy of the tumor, a diagnosis of small cell lung cancer was made. In addition, anti-Hu antibody was found in the patient's serum, leading to a diagnosis of paraneoplastic encephalomyelitis/sensory neuropathy. One course of chemotherapy (carboplatin + etoposide) was administered; however, the protocol was not completed because the patient developed severe pneumonia. Given that neurological symptoms usually precede a diagnosis of malignancy in paraneoplastic neurological syndromes, it is important that these are considered carefully, as they may contribute to early diagnosis and treatment. Here we report a rare case of severe central hypoventilation in paraneoplastic encephalomyelitis/sensory neuropathy.