John C. Murphy

Efficacy of the RADPAD Protective Drape During Real World Complex Percutaneous Coronary Intervention Procedures

The RADPAD is a lead-free surgical drape containing bismuth and barium that has been demonstrated to reduce scatter radiation exposure to primary operators during fluoroscopic procedures. It is not known to what degree the RADPAD reduces radiation exposure in operators who perform highly complex percutaneous coronary intervention (PCI) requiring prolonged fluoroscopic screening times. Sixty consecutive patients due to undergo elective complex PCI involving rotational atherectomy, multivessel PCI, or chronic total occlusions were randomized in a 1:1 pattern to have their procedures performed with and without the RADPAD drape in situ. Dosimetry was performed on the left arm of the primary operator. There were 40 cases of chronic total occlusion, including 28 with contralateral injections; 15 cases involving rotational atherectomy; and 5 cases of multivessel PCI. There was no significant difference in screening times or dose-area products between the 2 patient groups. Primary operator radiation dose relative to screening time (RADPAD: slope = 1.44, R² = 0.25; no RADPAD: slope = 4.60, R² = 0.26; analysis of covariance F = 4.81, p = 0.032) and dose-area product (RADPAD: slope = 0.003, R² = 0.26; no RADPAD: slope = 0.011, R² = 0.52; analysis of covariance F = 12.54, p = 0.008) was significantly smaller in the RADPAD cohort compared to the no-RADPAD group. In conclusion, the RADPAD significantly reduces radiation exposure to primary operators during prolonged, complex PCI cases.

Risk stratification of chest pain patients in the emergency department by a nurse utilizing a point of care protocol.

Objective Risk stratification of patients with ischaemic type chest pain assessed in the emergency department utilizing a point of care (POC) protocol. Methods Patient demographics, cardiac biomarkers, management and follow-up at 6 months were reviewed for patients seen over 20 months. Results Out of 546 patients, 351 (64%) were admitted. The diagnoses after admission were confirmed as acute myocardial infarction in 59 patients and unstable angina, (cTroponin T<0.09 ng/ml) in 92 patients. The c-statistic of the receiver operating curves for myocardial infarction (myocardial infarction, cTroponinT at 12 h >0.09 ng/ml) as determined by the POC assay was cTroponin I=0.884, CK-MB=0.883, myoglobin=0.845 and &bgr;-type natriuretic peptide (BNP)=0.755. The c-statistic for the same sample assessed by the hospital laboratory was cTroponin T=0.893: for CK-MB within 12 h of admission it was 0.918; the 12 h cTroponin T was 0.982 and within 24 h of admission NT pro-BNP was 0.789. POC BNP in patients admitted was 68 ng/l (median) vs. 24 ng/l (median) for those not admitted, (P<0.001). POC BNP for patients admitted with unstable angina (12 h cTroponin T <0.09 ng/ml) was 47 ng/l (median, P<0.001). At 6 months, 14 patients had died; five during admission, two within 30 days and seven up to 6 months. During admission two died from heart failure, two with respiratory tract infection and one from carcinoma. Of those not admitted one had died from asbestosis. Conclusion Risk stratification by a specialist nurse utilizing a POC protocol is an appropriate means of assessing patients with chest pain.

Guideliner® catheter—Friend or foe?

Performing percutaneous coronary intervention (PCI) in arteries with complex anatomy remains a clinical problem. In particular tortuosity within a coronary vessel is frequently encountered and can hamper delivery of balloons or stents to coronary stenoses. This has led to the development of a number of adjuvant devices to assist stent delivery in difficult cases. The safety profile of these novel devices remains to be clearly ascertained. The Guideliner® “child” support catheter is one such device and comprises of a 20‐cm silicon‐coated guide extension that assists delivery of stents in tortuous arteries when conventional techniques have failed. Initial reports suggest it is efficacious and no previous complications relating to the device have been published. We report the first complication involving the Guideliner® catheter which was encountered during primary PCI. We hypothesize regarding the mechanism of the complication and discuss the ways it may be avoided in the future.

Late aortic perforation with an atriasept device resulting in life‐threatening tamponade

Patients with compelling evidence of cryptogenic stroke due to patent foreamen ovale (PFO) are increasingly likely to be offered percutaneous closure of the defect. With improvements in technique there is now a high procedural success rate with low rates of periprocedural complications. Late complications are also rare, but include late perforation of the aortic root, which is rapidly progressive and potentially fatal. This has lead to the development of lower profile devices, which aim to reduce the risk of both early and late complications. At this stage, it is not clear if lower profile devices have safety profiles which are superior to the more established devices. We report the first case of late perforation of the aortic sinus by the lower profile Atriasept (Cardia) device presenting as life threatening cardiac tamponade in an adult who previously underwent percutaneous PFO closure.

An innovative piezoelectric-based method for measuring pulse wave velocity in patients with hypertension.

J Clin Hypertens (Greenwich). 2011;13:497–505.©2011 Wiley Periodicals, Inc.

Optimization of the precordial leads of the 12-lead electrocardiogram may improve detection of ST-segment elevation myocardial infarction

BACKGROUND For the assessment of patients with chest pain, the 12-lead electrocardiogram (ECG) is the initial investigation. Major management decisions are based on the ECG findings, both for attempted coronary artery revascularization and risk stratification. The aim of this study was to determine if the current 6 precordial leads (V(1)-V(6)) are optimally located for the detection of ST-segment elevation in ST-segment elevation myocardial infarction (STEMI). METHODS We analyzed 528 (38% anterior [200], 44% inferior [233], and 18% lateral [95]) patients with STEMI with both a 12-lead ECG and an 80-lead body surface map (BSM) ECG (Prime ECG, Heartscape Technologies, Bangor, Northern Ireland). Body surface map was recorded within 15 minutes of the 12-lead ECG during the acute event and before revascularization. ST-segment elevation of each lead on the BSM was compared with the corresponding 12-lead precordial leads (V(1)-V(6)) for anterior STEMI. In addition, for lateral STEMI, leads I and aVL of the BSM were also compared; and limb leads II, III, aVF of the BSM were compared with inferior unipolar BSM leads for inferior STEMI. Leads with the greatest mean ST-segment elevation were selected, and significance was determined by analysis of variance of the mean ST segment. RESULTS For anterior STEMI, leads V(1), V(2), 32, 42, 51, and 57 had the greatest mean ST elevation. These leads are located in the same horizontal plane as that of V(1) and V(2). Lead 32 had a significantly greater mean ST elevation than the corresponding precordial lead V(3) (P = .012); and leads 42, 51, and 57 were also significantly greater than corresponding leads V(4), V(5), V(6), respectively (P < .001). Similar findings were also found for lateral STEMI. For inferior STEMI, the limb leads of the BSM (II, III, and aVF) had the greatest mean ST-segment elevation; and lead III was significantly superior to the inferior unipolar leads (7, 17, 27, 37, 47, 55, and 61) of the BSM (P < .001). CONCLUSION Leads placed on a horizontal strip, in line with leads V(1) and V(2), provided the optimal placement for the diagnosis of anterior and lateral STEMI and appear superior to leads V(3), V(4), V(5), and V(6). This is of significant clinical interest, not only for ease and replication of lead placement but also may lead to increased recruitment of patients eligible for revascularization with none or borderline ST-segment elevation on the initial 12-lead ECG.

Preference for pharmacological management of patients with essential hypertension among senior physicians within Northern Ireland

In Northern Ireland, as elsewhere, hypertension remains a leading cause of morbidity and mortality. Controversy has existed for many years regarding the optimal pharmacological agents for the management of this condition. However, in the UK, both historical and more recent data show that in clinical practice beta-blockers and diuretics are the most commonly prescribed first-line agents for blood pressure (BP) management.1, 2 This pattern of prescribing will have been driven by issues such as cost and availability. In addition, a variety of guidelines from bodies such as British Hypertension Society (BHS), National Institute for Clinical Excellence (NICE) and the European Society of Hypertension will have influenced many doctors. However, these separate guidelines have been seen by some as incongruous, leading to confusion and further controversy.

A pressing matter--mediastinal fibrosis with near obliteration of the pulmonary arteries.

Idiopathic mediastinal fibrosis is a rare, histologically benign condition which often presents with symptoms attributable to compression of vital mediastinal structures. Diagnosis can be difficult and individualized treatments are required for patients, with possible intervention including pharmacotherapy, surgery, and percutaneous stenting. We present a case of idiopathic mediastinal fibrosis present in a 50‐year‐old woman as compression and near obliteration of the pulmonary arteries. A percutaneous approach was utilized with bilateral balloon expandable kissing stents simultaneous deployed from the main pulmonary artery to the right and left pulmonary arteries. There was instantaneous improvement in the pulmonary and systemic hemodynamics. Her immediate postprocedure course was complicated by reperfusion injury to the right lung, requiring intubation and ventilation. The patient made a full recovery and remains well at 6 months. Our case highlights the procedural and postprocedural difficulties that exist in such cases, and reinforces the value of endovascular stenting strategies in the management of patients with this rare condition.

EFFECTIVENESS OF A NURSE-LED HYPERTENSION CLINIC: PP.20.284

Background: Prevalence of hypertension in the population is projected to increase dramatically in the next decade. We sought to assess the effectiveness of a nurse-led hypertension clinic. Methods: A nurse-led hypertension clinic was implemented in July 2005 with the objectives of supervising up-titration of anti-hypertensive medication, establishing the presence of other modifiable risk factors, and providing lifestyle advice. The records of all patients who attended the nurse-led hypertension clinic between 1st July 2005 and 1st July 2008 were reviewed. Results: During the 3 year period 428 new patients (55% male) were referred to the clinic (mean age 58 ± 16 years), with a total of 938 clinic attendances; median number of attendances per patient 2 (range 1–10). Presence of co-existing modifiable risk factors for cardiovascular disease were identified at the first visit: 45 (11%) were current smokers and 240 (56%) were previously diagnosed with hyperlipidaemia (of which 140 (58%) had a total cholesterol level ≥ 5 mmol/L). Additionally, 91 (21%) had a body mass index of ≥ 30 kg/m2. Median systolic blood pressure recorded at first visit was 150 mmHg (interquartile range 140–166 mmHg). At the time of the first visit 273 (64%) were not taking any anti-hypertensive drugs, 47 (11%) were taking 1, 61 (14%) were taking 2, 41 (10%) were taking 3, and 6 (1%) were taking 4. Median systolic blood pressure recorded at last visit was 140 mmHg (132–155mmHg). The proportion of patients with a systolic blood pressure ≥ 150 mmHg fell from 55% (first visit) to 34% (last visit). Comparing the first and last visits in the 249 patients who returned for follow up appointments the mean systolic blood pressure reduction was 15 ± 25 mmHg, and mean percentage reduction was 8 ± 15 %. Conclusions: A nurse-led hypertension clinic is effective at reducing the systolic blood pressure of patients referred with hypertension. The clinic also provides an opportunity for intervention for other modifiable risk factors.

EFFECT OF RESPIRATION ON PULSE WAVE VELOCITY MEASUREMENTS IN THE ARM: PP.8.314

Introduction: Pulse Wave Velocity (PWV) in a vascular bed is determined significantly by the distending blood pressure (BP). Respiration influences systemic BP. Current guidelines for standardised measurement of PWV advise that recordings should be taken over a full respiratory cycle. No modern studies have quantified the degree to which respiration affects PWV measurements. We sought to assess the degree to which PWV in the arm will be affected by inspiration and expiration. Methods: Under standardised conditions PWV measurements were carried out in 10 volunteers during normal respiration. Thereafter PWV was measured during prolonged and help inspiration. Finally PWV was measured during prolonged and held expiration. Measurements were made in the carotid-radial segment (CRPWV) using applanation tonometry (SphygmoCor) and in the brachio-radial (BRPWV) segment using a piezoelectric system. Results: 10 volunteers completed the study, male = 6, mean age 31.2 years. None were on vasoactive medications. Mean CRPWV during normal respiration was 8.1 ± 0.6 m/sec. Mean BRPWV during normal respiration was 8.6 ± 1.4 m/sec. On the inspiration only studies a significant decrease was seen in CRPWV values (8.1 ± 0.6 m/sec vs 7.2 ± 0.7 p < 0.001, mean percentage change -11.2%) and BRPWV (8.6 ± 1.4 m/sec vs 7.8 ± 1.4 m/sec p = 0.005, mean percentage change -9.3%). During expiration CRPWV values increased from 8.1 ± 0.6 m/sec to 8.9 ± 0.8 m/sec (p = 0.002) with a mean percentage change from baseline was + 9.7%. BRPWV values also increased on the expiration only studies from 8.6 ± 1.4 m/sec to 9.3 ± 1.2 m/sec (p = 0.001), with a mean percentage change from baseline of + 7.8%. Conclusion: Deep respiration has significant effects on PWV measurements in the arm. This underlies the importance of measuring PWV in a relaxed patient over a full respiratory cycle.