The Effect of Open-Irrigated Radiofrequency Catheter Ablation of Atrial Fibrillation on Left Atrial Pressure and B-Type Natriuretic Peptide

Background Open-irrigated radiofrequency catheter ablation (oiRFA) of atrial fibrillation (AF) imposes a volume load and risk of pulmonary edema. We sought to assess the effect of volume administration during ablation on left atrial (LA) pressure and B-type natriuretic peptide (BNP). Methods LA pressure was measured via transseptal sheath at the beginning and end of 44 LA ablation procedures in 42 patients. BNP plasma levels were measured before and after 10 procedures. Results A median of 3,255 (interquartile range [IQR], 2,014)-mL saline was administered during the procedure. During LA ablation, the median fluid balance was +1,438 (IQR, 1,109) mL and LA pressure increased by median 3.7 (IQR, 5.9) mm Hg (P < 0.001). LA pressure did not change in the 19 procedures with furosemide administration (median ΔP = −0.3 [IQR, 7.1] mm Hg, P = 0.334). The correlation of LA pressure and fluid balance was weak (rs = 0.383, P = 0.021). BNP decreased in all four procedures starting in AF or atrial tachycardia and then converting to sinus rhythm (P = 0.068), and increased in all six procedures starting and finishing in sinus rhythm (P = 0.028). After ablation, symptomatic volume overload responding to diuresis occurred in three patients. Conclusions A substantial intravascular volume load during oiRFA can be absorbed with little change in LA pressure, such that LA pressure is not a reliable indicator of the fluid balance. Subsequent redistribution of the volume load imposes a risk after the procedure. Conversion to sinus rhythm may improve ability to acutely accommodate the volume load.

High proportion of healthcare-associated urinary tract infection in the absence of prior exposure to urinary catheter: a cross-sectional study

Exposure to urinary catheters is considered the most important risk factor for healthcare-associated urinary tract infection (UTI) and is associated with significant morbidity and substantial extra-costs. In this study, we assessed the impact of urinary catheterisation (UC) on symptomatic healthcare-associated UTI among hospitalized patients.

Fixed low-dose ultrasound-assisted catheter-directed thrombolysis for intermediate- and high-risk pulmonary embolism

AIMS No standardized local thrombolysis regimen exists for the treatment of pulmonary embolism (PE). We retrospectively investigated efficacy and safety of fixed low-dose ultrasound-assisted catheter-directed thrombolysis (USAT) for intermediate- and high-risk PE. METHODS AND RESULTS Fifty-two patients (65 ± 14 years) of whom 14 had high-risk PE (troponin positive in all) and 38 intermediate-risk PE (troponin positive in 91%) were treated with intravenous unfractionated heparin and USAT using 10 mg of recombinant tissue plasminogen activator per device over the course of 15 h. Bilateral USAT was performed in 83% of patients. During 3-month follow-up, two [3.8%; 95% confidence interval (CI) 0.5-13%] patients died (one from cardiogenic shock and one from recurrent PE). Major non-fatal bleeding occurred in two (3.8%; 95% CI, 0.5-13%) patients: one intrathoracic bleeding after cardiopulmonary resuscitation requiring transfusion, one intrapulmonary bleeding requiring lobectomy. Mean pulmonary artery pressure decreased from 37 ± 9 mmHg at baseline to 25 ± 8 mmHg at 15 h (P < 0.001) and cardiac index increased from 2.0 ± 0.7 to 2.7 ± 0.9 L/min/m(2) (P < 0.001). Echocardiographic right-to-left ventricular end-diastolic dimension ratio decreased from 1.42 ± 0.21 at baseline to 1.06 ± 0.23 at 24 h (n = 21; P < 0.001). The greatest haemodynamic benefit from USAT was found in patients with high-risk PE and in those with symptom duration < 14 days. CONCLUSION A standardized catheter intervention approach using fixed low-dose USAT for the treatment of intermediate- and high-risk PE was associated with rapid improvement in haemodynamic parameters and low rates of bleeding complications and mortality.

Fixed low-dose ultrasound-assisted catheter-directed thrombolysis followed by routine stenting of residual stenosis for acute ilio-femoral deep-vein thrombosis.

Patients with ilio-femoral deep-vein thrombosis (DVT) are at high risk of developing the post-thrombotic syndrome (PTS). In comparison to anticoagulation therapy alone, extended venography-guided catheter-directed thrombolysis without routine stenting of venous stenosis in patients with ilio-femoral DVT is associated with an increased risk of bleeding and a moderate reduction of PTS. We performed a prospective single-centre study to investigate safety, patency and incidence of PTS in patients with acute ilio-femoral DVT treated with fixed-dose ultrasound-assisted catheter-directed thrombolysis (USAT; 20 mg rt-PA during 15 hours) followed by routing stenting of venous stenosis, defined as residual luminal narrowing >50%, absent antegrade flow, or presence of collateral flow at the site of suspected stenosis. A total of 87 patients (age 46 ± 21 years, 60% women) were included. At 15 hours, thrombolysis success ≥50% was achieved in 67 (77%) patients. Venous stenting (mean 1.9 ± 1.3 stents) was performed in 70 (80%) patients, with the common iliac vein as the most frequent stenting site (83%). One major (1%; 95% CI, 0-6%) and 6 minor bleedings (7%; 95%CI, 3-14%) occurred. Primary and secondary patency rates at 1 year were 87% (95% CI, 74-94%) and 96% (95% CI, 88-99%), respectively. At three months, 88% (95% CI, 78-94%) of patients were free from PTS according to the Villalta scale, with a similar rate at one year (94%, 95% CI, 81-99%). In conclusion, a fixed-dose USAT regimen followed by routine stenting of underlying venous stenosis in patients with ilio-femoral DVT was associated with a low bleeding rate, high patency rates, and a low incidence of PTS.

Use of a perineural coiled catheter at the sciatic nerve in dogs after tibial plateau levelling osteotomy – preliminary observations

The analgesic effects of peripheral nerve blocks can be prolonged with the placement of perineural catheters allowing repeated injections of local anaesthetics in humans. The objectives of this study were to evaluate the clinical suitability of a perineural coiled catheter (PCC) at the sciatic nerve and to evaluate pain during the early post-operative period in dogs after tibial plateau levelling osteotomy. Pre-operatively, a combined block of the sciatic and the femoral nerves was performed under sonographic guidance (ropivacaine 0.5%; 0.3 mL kg−1 per nerve). Thereafter, a PCC was placed near the sciatic nerve. Carprofen (4 mg kg−1 intravenously) was administered at the end of anaesthesia. After surgery, all dogs were randomly assigned to receive four injections of ropivacaine (group R; 0.25%, 0.3 mL kg−1) or NaCl 0.9% (group C; 0.3 mL kg−1) every 6 h through the PCC. Pain was assessed by use of a visual analogue scale (VAS) and a multi-dimensional pain score (4Avet) before surgery (T-1), for 390 min (T0, T30, T60, T120, T180, T240, T300, T360 and T390) as well as 1 day after surgery (Day 1). Methadone (0.1 mg kg−1) was administered each time the VAS was ≥40 mm or the 4Avet was ≥5. At T390 dogs received buprenorphine (0.02 mg kg−1). Data were compared using Mann–Whitney rank sum tests and repeated measures analysis of variance. Regardless of group allocation, 55% of dogs required methadone. VAS was significantly lower at T390 (P = 0.003), and at Day 1 (P = 0.002) and so was 4Avet at Day 1 (P = 0.012) in group R than in group C. Bleeding occurred in one dog at PCC placement and PCC dislodged six times of 47 PCCs placed. Minor complications occurred with PCC but allowed four repeated administrations of ropivacaine or saline over 24 h in 91.5% of the cases.

Benefit of heparin in peripheral venous and arterial catheters: systematic review and meta-analysis of randomised controlled trials

Objective: To evaluate the effect of heparin on duration of catheter patency and on prevention of complications associated with use of peripheral venous and arterial catheters.

Percutaneous removal of a knotted pulmonary artery catheter using a tracheostomy dilator

This case report describes removal of a knotted, subclavian, pulmonary artery catheter using a tracheostomy dilator. With this simple method an invasive procedure might be averted.

Epicardial phrenic nerve displacement during catheter ablation of atrial and ventricular arrhythmias: procedural experience and outcomes.

BACKGROUND Arrhythmia origin in close proximity to the phrenic nerve (PN) can hinder successful catheter ablation. We describe our approach with epicardial PN displacement in such instances. METHODS AND RESULTS PN displacement via percutaneous pericardial access was attempted in 13 patients (age 49±16 years, 9 females) with either atrial tachycardia (6 patients) or atrial fibrillation triggered from a superior vena cava focus (1 patient) adjacent to the right PN or epicardial ventricular tachycardia origin adjacent to the left PN (6 patients). An epicardially placed steerable sheath/4 mm-catheter combination (5 patients) or a vascular or an esophageal balloon (8 patients) was ultimately successful. Balloon placement was often difficult requiring manipulation via a steerable sheath. In 2 ventricular tachycardia cases, absence of PN capture was achieved only once the balloon was directly over the ablation catheter. In 3 atrial tachycardia patients, PN displacement was not possible with a balloon; however, a steerable sheath/catheter combination was ultimately successful. PN displacement allowed acute abolishment of all targeted arrhythmias. No PN injury occurred acutely or in follow up. Two patients developed acute complications (pleuro-pericardial fistula 1 and pericardial bleeding 1). Survival free of target arrhythmia was achieved in all atrial tachycardia patients; however, a nontargeted ventricular tachycardia recurred in 1 patient at a median of 13 months' follow up. CONCLUSIONS Arrhythmias originating in close proximity to the PN can be targeted successfully with PN displacement with an epicardially placed steerable sheath/catheter combination, or balloon, but this strategy can be difficult to implement. Better tools for phrenic nerve protection are desirable.

Long Term Outcomes Following Catheter Ablation of Ventricular Tachycardia in Patients with and without Structural Heart Disease.

BACKGROUND Long-term outcomes following ventricular tachycardia (VT) ablation are sparsely described. OBJECTIVES To describe long term prognosis following VT ablation in patients with no structural heart disease (no SHD), ischemic (ICM) and non-ischemic cardiomyopathy (NICM). METHODS Consecutive patients (n=695; no SHD 98, ICM 358, NICM 239 patients) ablated for sustained VT were followed for a median of 6 years. Acute procedural parameters (complete success [non-inducibility of any VT]) and outcomes after multiple procedures were reported. RESULTS Compared with patients with no SHD or NICM, ICM patients were the oldest, had more males, lowest left ventricular ejection fraction (LVEF), highest drug failures, VT storms and number of inducible VTs. Complete procedure success was highest in no SHD, compared ICM and NICM patients (79%, 56%, 60% respectively, P<0.001). At 6 years, ventricular arrhythmia (VA)-free survival was highest in no SHD (77%) than ICM (54%) and NICM (38%, P<0.001) and overall survival was lowest in ICM (48%), followed by NICM (74%) and no SHD patients (100%, P<0.001). Age, LVEF, presence of SHD, acute procedural success (non-inducibility of any VT), major complications, need for non-radiofrequency ablation modalities, and VA recurrence were independently associated with all cause mortality. CONCLUSIONS Long term follow up following VT ablation shows excellent prognosis in the absence of SHD, highest VA recurrence and transplantation in NICM and highest mortality in patients with ICM. The extremely low mortality for those without SHD suggests that VT in this population is very rarely an initial presentation of a myopathic process.

Survey of intensive care nurses' knowledge relating to the pulmonary artery catheter

In 2003 there was an increase in the use of pulmonary artery catheters in Australia from 12, 000 to 16, 000 units in intensive care and peri-operative care. This survey of intensive care nurses in five intensive care units in Queensland addressed knowledge of use, safety and complications of the pulmonary artery catheter, using a previously validated 31 question multiple choice survey. One hundred and thirty-nine questionnaires were completed, a response rate of 46%. The mean score was 13.3, standard deviation +/-4.2 out of a total of 31 (42.8% correct). The range was 4 to 25. Scores were significantly higher in those participants with more ICU experience, higher nursing grade, a higher self-assessed level of knowledge and greater frequency of PAC supervision. There was no significant correlation between total score and hospital- or university-based education, or total score and public or private hospital participants. Fifty-one per cent were unable to correctly identify the significant pressure change as the catheter is advanced from the right ventricle to the pulmonary artery.

Anatomical basis for the cardiac interventional electrophysiologist

The establishment of radiofrequency catheter ablation techniques as the mainstay in the treatment of tachycardia has renewed new interest in cardiac anatomy. The interventional arrhythmologist has drawn attention not only to the gross anatomic details of the heart but also to architectural and histological characteristics of various cardiac regions that are relevant to the development or recurrence of tachyarrhythmias and procedural related complications of catheter ablation. In this review, therefore, we discuss some anatomic landmarks commonly used in catheter ablations including the terminal crest, sinus node region, Koch’s triangle, cavotricuspid isthmus, Eustachian ridge and valve, pulmonary venous orifices, venoatrial junctions, and ventricular outflow tracts. We also discuss the anatomical features of important structures in the vicinity of the atria and pulmonary veins, such as the esophagus and phrenic nerves. This paper provides basic anatomic information to improve understanding of the mapping and ablative procedures for cardiac interventional electrophysiologists.

Left atrial anatomy relevant to catheter ablation

The rapid development of interventional procedures for the treatment of arrhythmias in humans, especially the use of catheter ablation techniques, has renewed interest in cardiac anatomy. Although the substrates of atrial fibrillation (AF), its initiation and maintenance, remain to be fully elucidated, catheter ablation in the left atrium (LA) has become a common therapeutic option for patients with this arrhythmia. Using ablation catheters, various isolation lines and focal targets are created, the majority of which are based on gross anatomical, electroanatomical, and myoarchitectual patterns of the left atrial wall. Our aim was therefore to review the gross morphological and architectural features of the LA and their relations to extracardiac structures. The latter have also become relevant because extracardiac complications of AF ablation can occur, due to injuries to the phrenic and vagal plexus nerves, adjacent coronary arteries, or the esophageal wall causing devastating consequences.

Aspects Related to Venous Ulcer Healing and its Influence on Quality of Life

Nowadays, the varicose ulcers (VUs) are one of the most worrying leg ulcers and are an important problem in global public health, with high costs related to the treatment and its complications. Moreover, the quality of life (QOL) of the patient could be affected by pain, sleep disorders, functional impairment, depression and isolation. The VUs patient care is complex and it is necessary to know the aspects that contribute to the healing process for developing effective strategies. The members of the multidisciplinary health team should identify sociodemographic, clinical and care aspects that interfere in tissue repair and therefore impacting the QOL. Self-efficacy, adherence to treatment and self-esteem are other important aspects also related to healing and QOL, with implications for health care and the multidisciplinary team. To sum up, the use of multidisciplinary protocols allows the systematization of care for people with VUs in order to standardize therapeutic interventions with the aim to decrease the healing process time and, as a consequence, to improve the QOL.