Psychological distress mediates the effects of socio-demographic and clinical characteristics on the physical health component of health-related quality of life in patients with coronary heart disease.

BACKGROUND: This study aimed to examine the mediating role of psychological distress in the relationship between the physical health component of health-related quality of life (HRQoL) of coronary heart disease patients and their socio-demographic and clinical characteristics. METHODS: This was a cross-sectional study conducted from March 2009 to July 2010 with a total of 420 participants recruited from two hospital-based phase II cardiac rehabilitation centres. Participants' socio-demographic variables, self-reported medical history data, level of psychological distress, perceived social support, and HRQoL were collected by means of a structured questionnaire. Body weight and height, blood pressure and clinical data including fasting blood glucose, triglycerides, and low- and high-density lipoprotein cholesterol were also collected. Exploratory univariate analyses and multivariable regressions were conducted to identify socio-demographic and clinical determinants of the physical health component of HRQoL. Path analyses were then performed to examine the mediating role of psychological distress in the relationship between the physical health component of HRQoL and the determinants. RESULTS: Path analysis revealed that age, sex, perceived social support, history of angina, and dyslipidaemia had both direct effect and indirect effect through psychological distress on the physical health component of HRQoL. Obesity and impaired left ventricular function only affected the physical health component of HRQoL directly, whereas household income only affected it indirectly, through psychological distress. CONCLUSION: Psychological distress mediates the effects of some socio-demographic and clinical variables of CHD patients on the physical health component of HRQoL. Our findings have important implications for rehabilitation care for people with CHD in order to enhance their HRQoL.

Inner lumen mapping catheter-facilitated big cryoballoon treatment for atrial fibrillation shortens procedural duration and fluoroscopic exposure with comparable mid-term efficacy.

PURPOSE: This study aims to investigate whether the use of a novel inner lumen circular mapping catheter (IMC) can shorten the procedural duration and fluoroscopic exposure of the single transseptal big cryoballoon (CB) pulmonary vein isolation (PVI) procedures in patients with atrial fibrillation (AF). METHODS: This is a prospective non-randomized case-control study. Forty-two patients (28 men, mean age 55.7 ± 12.1) with drug-refractory paroxysmal or persistent AF and underwent CB PVI procedures were divided into Group A (conventional single transseptal big CB approach, n = 21) and Group B (IMC-facilitated approach, n = 21). They were compared in the co-primary endpoints: (1) procedural duration and (2) fluoroscopic exposure and secondary endpoints: (1) 6-month AF-free survival and (2) number of cryo-applications. RESULTS: Both the procedural duration (162 ± 26 vs. 215 ± 25 min; p < 0.001) and fluoroscopic exposure (44.1 ± 10.4 vs. 56.8 ± 11.7 min; p = 0.001) were significantly shorter in Group B than Group A patients. With multivariate stepwise regression, only the use of IMC was an independent predictor for procedural duration (ß = -59; 95 % CI, -84.1 to -33.8; p < 0.001) and fluoroscopic exposure (ß = -16.9; 95 % CI, -28.4 to -5.4; p = 0.006). The number of cryo-applications was significantly fewer in Group B than Group A patients (median 8 vs. 11; p = 0.001). There was no significant difference in the 6-month AF-free survival between the two approaches (57 % vs. 71 %; p = 0.351). CONCLUSIONS: Compared to conventional single transseptal big CB PVI procedures, the use of IMC may reduce procedural duration, fluoroscopic exposure and the number of cryo-applications with comparable mid-term efficacy.

Treatment of atrioventricular nodal re-entrant tachycardia by cryoablation with an 8-mm-tip catheter versus radiofrequency ablation.

PURPOSE: Catheter cryoablation (CRYO) may eliminate inadvertent atrioventricular block (AVB) in the treatment of atrioventricular nodal reentrant tachycardia (AVNRT). However, higher recurrence was observed with CRYO delivered by 4 mm or 6 mm-tip catheter. This study was performed to investigate whether a comparably low treatment failure and recurrence rate as in radiofrequency (RF) ablation is achievable by CRYO with an 8-mm-tip catheter. METHODS: This is a retrospective case-control study including 40 patients with AVNRT treated with CRYO (n = 20) using an 8 mm-tip catheter or RF ablation (n = 20) from March 2009 to March 2011. Treatment failure was defined as the composite of acute procedural failure including inadvertent permanent AVB and documented recurrence. RESULTS: Acute procedural success of 90% (18/20) and 95% (19/20) were achieved in CRYO and RF ablation group, respectively (p = 0.998), with no permanent AVB in either group. With Kaplan-Meier analysis, there was no significant difference between the treatment groups in terms of recurrence rate (5.6% [1/18] vs. 0%; log-rank test p = 0.304) and treatment failure (15% [3/20] vs. 5% [1/20]; log-rank test p = 0.301). Shorter fluoroscopy time (15 ± 8.6 vs. 25.2 ± 12.1 min; p = 0.005) and more energy applications (median 4 [2-15] vs. 2 [1-8]; p = 0.005) were observed in the CRYO group compared with RF ablation group. CONCLUSIONS: Compared to RF ablation, CRYO with an 8-mm-tip catheter for treating AVNRT achieves a comparable acute procedural success, comparably low recurrence rate and composite endpoint of treatment failure. Shorter fluoroscopy time and more energy applications were observed in the CRYO group.

Utility of a novel pacing guidewire in pre-implantation testing at different left ventricular sites in cardiac resynchronization therapy procedures.

PURPOSE: This study aimed to evaluate the utility of a novel pacing guidewire in pre-implantation testing of different left ventricular (LV) sites during cardiac resynchronization therapy (CRT) procedures. METHODS: Ten consecutive patients (8 male, mean age 65.8 ± 4.9) undergoing CRT procedures were studied. Pacing threshold and R-wave sensing measured by the guidewire and LV lead at different LV sites were compared. RESULTS: Thirty sites (6 apical, 13 middle, and 11 basal; 15 lateral and 15 anterior) were tested. There was significant correlation between pacing threshold (r = 0.878, p < 0.0001), and R-wave sensing (r = 0.896, p < 0.0001) obtained by guidewire and those obtained by LV lead. Separating into lateral and anterior sites, significant correlation was also found in pacing threshold (lateral r = 0.658, p = 0.008; anterior r = 0.886, p < 0.0001) and R-wave sensing (lateral r = 0.887, p < 0.0001; anterior 0.865, p < 0.0001). For basal and middle sites, significant correlation was found in pacing threshold (basal r = 0.890, p < 0.0001; middle r = 0.878, p < 0.0001), and R-wave sensing (basal r = 0.930, p < 0.0001; middle r = 0.823, p < 0.001). No and borderline correlation was found in pacing threshold (r = 0.548, p = 0.26) and R-wave sensing (r = 0.835, p = 0.039), respectively, for apical sites. Concordance rate for the presence of phrenic nerve stimulation at high pacing output was 87%. CONCLUSION: The accuracy of the novel pacing guidewire in pre-implantation testing in CRT procedures is site-dependent. There was good correlation with LV lead in the measurement of pacing threshold and R-wave sensing at basal and middle sites, but not apical sites. Presence of phrenic nerve stimulation can be predicted by guidewire testing with high accuracy.

Persistent iatrogenic atrial septal defect after pulmonary vein isolation by cryoballoon: an under-recognized complication.

AIMS: Iatrogenic atrial septal defect (IASD) has been reported as a complication of transseptal puncture. This study aims to investigate the incidence, echocardiographic characteristics, and clinical outcome of persistent IASD after pulmonary vein isolation (PVI) by cryoballoon catheter delivered by a large transseptal sheath. METHODS AND RESULTS: Thirteen patients (9 males, mean age 54.9 ± 13.0) with paroxysmal (10) or persistent (3) atrial fibrillation underwent PVI with cryoballoon catheter. Single transseptal puncture was performed with a BRK-1 shaped Brockenbrough needle and an 8 F sheath which was exchanged for a steerable transseptal sheath (15 F outer diameter and 12 F inner diameter) with the support of a stiff guidewire. Pulmonary vein isolation was performed with a 28 mm cryoballoon catheter. The incidence of persistent IASD was evaluated by transoesophageal echocardiography performed at 6 and 9 months after the procedure. At 6 months, five (38%) patients had persistent IASD with left-to-right shunt. The mean size of the IASD was 5.5 ± 2.4 mm. At 9 months, one patient had closure of the IASD and four (31%) patients had persistent IASD with mean size of 4.6 ± 1.4 mm. No patient died or suffered clinically from paradoxical embolism. CONCLUSIONS: Persistent IASD is a common complication after PVI by cryoballoon catheter. Only left-to-right, but not right-to-left, interatrial shunting occurred as a result of the IASD. There was no clinical occurrence of paradoxical embolism. Patients should be screened for this complication after cryoballoon procedures and regular reassessment with echocardiographic or other techniques should be performed for monitoring.

Cryoablation versus radiofrequency ablation for atrioventricular nodal reentrant tachycardia: patient pain perception and operator stress.

BACKGROUND: Cryoablation (CRYO) is an alternative to radiofrequency (RF) ablation in the treatment of atrioventricular nodal reentrant tachycardia (AVNRT). This study aims to evaluate the differences in patient pain perception and operator stress between CRYO and RF ablation in the treatment of AVNRT. METHODS: Patients with supraventricular tachycardia underwent electrophysiology study. Twenty patients (eight males, age 46.5 ± 12.5 years) diagnosed with AVNRT were randomized to receive CRYO (11) with a 6-mm-tip catheter or RF (nine) with a 4-mm-tip catheter. Patients' pain perception and operator stress were assessed with a visual analogue scale (VAS) from 0 to 10 at the end of procedure. RESULTS: There was no significant difference in acute procedural success (CRYO 100% vs RF 89%, P = 0.257). There was no complication of permanent atrioventricular block in either group. The number of energy applications was significantly higher in the CRYO group (2.8 ± 1.2 vs 1.6 ± 0.9, P = 0.02). The fluoroscopic time was significantly reduced in the CRYO group (6.0 ± 4.9 vs 10.9 ± 5.4 minutes, P = 0.049) with no difference in procedure time (CRYO 49.3 ± 12.5 vs RF 54.5 ± 17.0 minutes, P = 0.462). Patients in the CRYO group experienced significantly less pain than patients in the RF group (VAS 2.3 ± 2.8 vs 5.4 ± 3.4, P = 0.024). The operator also experienced significantly less stress during CRYO than RF (VAS 1.9 ± 0.8 vs 6.2 ± 1.6, P < 0.001). There was no recurrence in both groups at 6-month follow-up. CONCLUSIONS: CRYO, as compared with RF, produces less pain in patients and less stress in operator in the treatment of AVNRT.

Echocardiographic mapping of left ventricular resynchronization during cardiac resynchronization therapy procedures.

BACKGROUND: Cardiac resynchronization therapy (CRT) is an effective electrical therapy for patients with moderate to severe heart failure and cardiac dyssynchrony. This study aimed to investigate the degree of acute left ventricular (LV) resynchronization with biventricular pacing (BVP) at different LV sites and to examine the feasibility of performing transthoracic echocardiography (TTE) to quantify acute LV resynchronization during CRT procedure. METHODS: Fourteen patients with NYHA Class III-IV heart failure, LV ejection fraction < or = 35%, QRS duration > or = 120 ms and septal-lateral delay (SLD) > or = 60 ms on tissue Doppler imaging (TDI), underwent CRT implant. TDI was obtained from three apical views during BVP at each accessible LV site and SLD during BVP was derived. Synchronicity gain index (Sg) by SLD was defined as (1 + (SLD at baseline--SLD at BVP)/SLD at baseline). RESULTS: Seventy-two sites were studied. Positive resynchronization (R+, Sg > 1) was found in 42 (58%) sites. R+ was more likely in posterior or lateral than anterior LV sites (66% vs. 36%, P < 0.001). Concordance of empirical LV lead implantation sites and sites with R+ was 50% (7/14). CONCLUSIONS: The degree of acute LV resynchronization by BVP depends on LV lead location and empirical implantation of LV lead results in only 50% concordance with R+. Performing TTE during CRT implantation is feasible to identify LV sites with positive resynchronization.

Treatment of atrioventricular nodal re-entrant tachycardia by cryoablation with a 6 mm-tip catheter vs. radiofrequency ablation.

AIMS: To compare recurrence rate and other procedural characteristics in patients undergoing atrioventricular nodal re-entrant tachycardia (AVNRT) treatment with catheter cryoablation (CRYO) delivered by 6 mm-tip catheter or radiofrequency (RF) ablation. METHODS AND RESULTS: This is a retrospective case-control study including 80 patients with AVNRT treated with CRYO from March 2002 to June 2008. They were compared with another 80 consecutive patients who underwent RF ablation for AVNRT within the same period. Procedural success of 97.5 and 95% were achieved in CRYO and RF group, respectively. There was no permanent atrioventricular block (AVB) in the CRYO group, whereas two (2.5%) patients developed permanent first-degree or second-degree AVB in RF group (P = 0.155). Higher recurrence was found in the CRYO group (9 vs. 1.3%; P = 0.032) with no difference in the composite endpoint of procedural failure and recurrence between the groups (P = 0.263). There was significantly shorter fluoroscopy time (18.6 +/- 10.8 vs. 25.9 +/- 17.0 min; P = 0.002) and more energy applications required (3.1 +/- 1.7 vs. 1.9 +/- 1.1; P < 0.001) in the CRYO than the RF group. CONCLUSION: Compared with RF ablation, CRYO with 6 mm-tip catheter for treating AVNRT results in higher recurrence and potentially lower incidence of permanent AVB. Fluoroscopy time has been shown to be reduced by CRYO.

A new ECG criterion to identify takotsubo cardiomyopathy from anterior myocardial infarction: role of inferior leads.

With the exception of contrast-enhanced cardiovascular magnetic resonance imaging, clear distinction of takotsubo cardiomyopathy from anterior wall myocardial infarction cannot be achieved currently by simple and noninvasive tests. The aim of this study was to examine the role of inferior ECG leads in distinguishing these two conditions. From January 2004 to June 2006, eight female patients suffering from takotsubo cardiomyopathy were identified by the Mayo Clinic criteria. The clinical and ECG features were compared with 27 consecutive sex- and age-matched patients with anterior wall myocardial infarction admitted to the Coronary Care Unit within the same period. The observed ECG features were then verified with that of 62 published cases of takotsubo cardiomyopathy. Takotsubo cardiomyopathy patients had similar left ventricular ejection fraction (35.0% +/- 5.7% vs 38.2% +/- 6.4%, P = 0.829), lower peak creatinine kinase level (461 +/- 330 U/l vs 2723 +/- 1826 U/l, P = 0.020), more ST-segment elevation in the inferior leads (50% vs 7.4%, P = 0.016), and virtually no ST-segment depression in inferior leads (0% vs 48.2%, P = 0.015) compared with patients who had anterior wall myocardial infarction. ST-segment elevation of >or=1.0 mm in lead II had 62.5% sensitivity and 92.6% specificity in detecting takotsubo cardiomyopathy. The observed ECG characteristics were comparable with those in the literature. In patients who present with anterior wall myocardial infarction, the absence of ST-segment depression or ST-segment elevation in inferior leads, especially if the ST-segment in lead II >or= III, is highly suggestive of takotsubo cardiomyopathy.

Tachycardia amongst subjects recovering from severe acute respiratory syndrome (SARS).

SARS is a new infection in human. Patients recovering from SARS had palpitation in the form of sinus tachycardia. This study to identify the possible causes for the tachycardia excluded active disease, thyroid dysfunction, haematological, cardiac, autonomic and significant pulmonary defect at 2 months from onset of disease. The symptomatology was attributed to physical deconditioning and anxiety state. Physical and psychological fitness should be restored with rehabilitation.

Possible central nervous system infection by SARS coronavirus.

On day 22 of illness, generalized tonic-clonic convulsion developed in a 32-year-old woman with severe acute respiratory syndrome (SARS). Cerebrospinal fluid tested positive for SARS coronavirus (SARS-CoV) by reverse transcriptase-polymerase chain reaction. SARS-CoV may have caused an infection in the central nervous system in this patient.