Electrocardiogram-gated Kilohertz Visualisation (EKV) Ultrasound Allows Assessment of Neonatal Cardiac Structural and Functional Maturation and Longitudinal Evaluation of Regeneration After Injury.

The small size and high heart rate of the neonatal mouse heart makes structural and functional characterisation particularly challenging. Here, we describe application of electrocardiogram-gated kilohertz visualisation (EKV) ultrasound imaging with high spatio-temporal resolution to non-invasively characterise the post-natal mouse heart during normal growth and regeneration after injury. The 2-D images of the left ventricle (LV) acquired across the cardiac cycle from post-natal day 1 (P1) to P42 revealed significant changes in LV mass from P8 that coincided with a switch from hyperplastic to hypertrophic growth and correlated with ex vivo LV weight. Remodelling of the LV was indicated between P8 and P21 when LV mass and cardiomyocyte size increased with no accompanying change in LV wall thickness. Whereas Doppler imaging showed the expected switch from LV filling driven by atrial contraction to filling by LV relaxation during post-natal week 1, systolic function was retained at the same level from P1 to P42. EKV ultrasound imaging also revealed loss of systolic function after induction of myocardial infarction at P1 and regain of function associated with regeneration of the myocardium by P21. EKV ultrasound imaging thus offers a rapid and convenient method for routine non-invasive characterisation of the neonatal mouse heart.

The appropriateness of coronary investigation in myocardial injury and type 2 myocardial infarction (ACT-2): A randomized trial design.

BACKGROUND: Elevated troponin level findings among patients presenting with suspected acute coronary syndrome (ACS) or another intercurrent illness undeniably identifies patients at increased risk of mortality. Whilst enhancing our capacity to discriminate risk, the use of high-sensitivity troponin assays frequently identifies patients with myocardial injury (i.e. troponin rise without acute signs of myocardial ischemia) or type 2 myocardial infarction (T2MI; oxygen supply-demand imbalance). This leads to the clinically challenging task of distinguishing type 1 myocardial infarction (T1MI; coronary plaque rupture) from myocardial injury and T2MI in the context of concurrent acute illness. Diagnostic discernment in this context is crucial because MI classification has implications for further investigation and care. Early invasive management is of well-established benefit among patients with T1MI. However, the appropriateness of this investigation in the heterogeneous context of T2MI, where there is high competing mortality risk, remains unknown. Although coronary angiography in T2MI is advocated by some, there is insufficient evidence in existing literature to support this opinion as highlighted by current national guidelines. OBJECTIVE: The objective is to evaluate the clinical and economic impact of early invasive management with coronary angiography in T2MI in terms of all-cause mortality and cost effectiveness. DESIGN: This prospective, pragmatic, multicenter, randomized trial among patients with suspected supply demand ischemia leading to troponin elevation (n=1,800; T2MI [1,500], chronic myocardial injury [300]) compares the impact of invasive angiography (or computed tomography angiography as per local preference) within 5 days of randomization versus conservative management (with or without functional testing at clinician discretion) on all-cause mortality by 2 years. Randomized treatment allocation will be stratified by baseline estimated risk of mortality using the Acute Physiology, Age, and Chronic Health Evaluation (APACHE) III risk score. Cost-effectiveness will be evaluated by follow-up on clinical events, quality of life, and resource utilization over 24 months. SUMMARY: Ascertaining the most appropriate first-line investigative strategy for these commonly encountered high-risk T2MI patients in a randomized comparative study will be pivotal in informing evidence-based guidelines that lead to better patient and health care outcomes.

Incidence, predictors, management and outcomes of coronary perforations.

OBJECTIVES: We examined the contemporary incidence, types, predictors, angiographic characteristics, management and outcomes of coronary perforation. BACKGROUND: Coronary perforation is a rare, but important, complication of percutaneous coronary intervention (PCI). There is lack of data on perforations stratified as large and distal vessel perforations. METHODS: Retrospective, observational cohort study of all patients who underwent PCI at a high volume, tertiary hospital between the years 2009 and 2016. Angiograms of all coronary perforation cases were reviewed to determine the mechanism, type, and management of perforation. Risk-adjusted periprocedural complication rates were compared between patients with and without coronary perforation. One-year mortality outcomes of patients with large vessel vs. distal vessel perforation were also examined. RESULTS: Coronary perforation occurred in 68 of 13,339 PCIs (0.51%) performed during the study period: 51 (75%) were large vessel perforations and 17 (25%) distal vessel perforations. Most (67%) large vessel perforations were due to balloon/stent inflation, whereas most (94%) distal vessel perforations were due to guidewire exit. Patients with coronary perforations had significantly higher risk for periprocedural complications (adjusted odds ratio 7.57; 95% CI: 4.22-13.50; P < 0.001). Only one patient with large vessel perforation required emergency cardiac surgery, yet in-hospital mortality was high with both large vessel (7.8%) and distal vessel (11.8%) perforations. CONCLUSIONS: Coronary perforation is an infrequent, but potentially severe PCI complication. Most coronary perforations are large vessel perforations. Although coronary perforations rarely lead to emergency cardiac surgery, both distal vessel and large vessel perforations are associated with high in-hospital mortality, highlighting the importance of prevention.

Assessment of Cardiac Lead Perforation: Comparison Among Chest Radiography, Transthoracic Echocardiography and Electrocardiography-gated Contrast-enhanced Cardiac CT.

OBJECTIVES: Cardiac lead perforation is a rare but potentially life-threatening event. The purpose of this study was to investigate the diagnostic performances of chest radiography, transthoracic echocardiography (TTE) and electrocardiography (ECG)-gated contrast-enhanced cardiac CT in the assessment of cardiac lead perforation. METHODS: This retrospective study was approved by the ethics review board of Sun Yat-Sen Memorial Hospital at Sun Yat-Sen University (Guangzhou, China), and the need to obtain informed consent was waived. Between May 2010 and Oct 2017, 52 patients were clinically suspected to have a cardiac lead perforation and received chest radiography, TTE and ECG-gated contrast-enhanced cardiac CT. Among them, 13 patients were identified as having cardiac lead perforation. The diagnostic performances of these three modalities were evaluated by receiver-operating characteristic (ROC) curves using a composite reference standard of surgical and electrophysiological results and clinical follow-up. The areas under ROCs (AUROCs) were compared with the McNemar test. RESULTS: The accuracies of chest radiography, TTE and ECG-gated contrast-enhanced cardiac CT imaging for the diagnosis of cardiac lead perforation were 73.1%, 82.7% and 98.1%, respectively. ECG-gated contrast-enhanced cardiac CT had a higher AUROC than chest radiography (p < 0.001) and TTE (p < 0.001). CONCLUSIONS: ECG-gated contrast-enhanced cardiac CT is superior to both chest radiography and TTE imaging for the assessment of cardiac lead perforation. KEY POINTS: • ECG-gated contrast-enhanced cardiac CT has an accuracy of 98.1% in the diagnosis of cardiac lead perforation. • The AUROC of ECG-gated contrast-enhanced cardiac CT is higher than those of chest radiography and TTE imaging. • ECG-gated contrast-enhanced cardiac CT imaging has better diagnostic performance than both chest radiography and TTE imaging for the assessment of cardiac lead perforation.

Cost-effectiveness of the Cardiac Component of the Focused Assessment of Sonography in Trauma Examination in Blunt Trauma.

BACKGROUND: Blunt cardiac injury severe enough to require surgical intervention (sBCI) is an exceedingly rare event occurring in approximately 1 out of every 1600 trauma patients. While performing the cardiac component of the Focused Assessment of Sonography in Trauma (cFAST) exam is effective in penetrating trauma, it is unclear whether it is of value in blunt trauma given the low prevalence of sBCI, the imperfect test characteristics of the FAST exam, and the rate of incidental pericardial effusion. OBJECTIVE: The objective was to determine through decision analysis whether performing the cFAST exam is cost-effective in the evaluation of hypotensive and normotensive blunt trauma patients. METHODS: We created two decision analytic models using commercially available software (TreeAgePro2011) to evaluate the cost-effectiveness of the cFAST in hypotensive (systolic blood pressure <90 mm Hg) and normotensive blunt trauma patients. Clinical probabilities were obtained from published data. Costs were estimated from Medicare reimbursement and charge data. The willingness-to-pay threshold was $50,000/quality-adjusted life-years (QALYs). Sensitivity analyses were performed over plausible ranges using available literature. RESULTS: In hypotensive patients, for the base case scenario of a 34-year-old with blunt trauma, the cFAST strategy had a cost of $42,882.70 and an effectiveness of 25.3597 QALYs, whereas the no cFAST strategy had a cost of $42,753.52 and an effectiveness of 25.3532 QALYs. The incremental cost-effectiveness ratio (ICER) was $19,918/QALY. For normotensive patients the cFAST strategy had a cost of $18,331.03 and an effectiveness of 23.2817 QALYs, whereas the no cFAST strategy had a cost of $18,207.58 and an effectiveness of 23.2814 QALYs. The ICER was $465,867/QALY. In the sensitivity analyses, age, probability of death from sBCI with prompt treatment, and probability of sBCI were the main drivers of variability in the model outcomes. CONCLUSIONS: The cFAST for blunt trauma is cost-effective for hypotensive but not for normotensive patients. The ICER for hypotensive patients was more than 20 times higher than the ICER for normotensive patients. Our results suggest that performing the cFAST exam may not be an effective use of resources in normotensive blunt trauma patients.

Acquired ventricular septal defect: a rare sequel of blunt chest trauma in a 7-year-old boy.

Ventricular septal defect (VSD) is the most common congenital cardiac lesion encountered worldwide. Only very rarely is it acquired, and causation through blunt injury in a child is extremely rare. A previously healthy 7-year-old boy suffered blunt chest trauma while at play. He presented 11 days later with features of acute congestive cardiac failure. Two-dimensional echocardiographic examination revealed a mid-muscular VSD. The connection between the defect and the trauma was not initially appreciated. Facilities for required urgent open-heart surgery were not available. Cardiac failure was refractory to anti-failure therapy. His clinical condition steadily worsened, and he succumbed after 20 days on admission. We conclude that a diagnosis of traumatic VSD, though rare, should be considered in any previously well child presenting in acute congestive cardiac failure following blunt trauma to the chest. Any such patient should undergo careful echocardiographic evaluation. There is an urgent need for facilities for open-heart surgery to be more readily available and accessible in Nigeria.

Role of speckle tracking imaging in the assessment of myocardial regional ventricular function in experimental blunt cardiac injury.

PURPOSE: To evaluate the usefulness and information collecting ability of speckle tracking imaging techniques in the assessment of myocardial regional ventricular contractility in a rabbit model with blunt cardiac injury. METHODS: Fifteen healthy New Zealand rabbits weighing (2.70 ±0.28) kg were anesthetized (3% pentobarbital sodium/i.v) and impacted using the BIM-II biological impact machine to induce myocardial contusion (MC). Hemodynamic parameters, such as heart rate, systolic pressure, mean arterial pressure, diastolic pressure and central venous pressure, were determined before and after MC. Further, parameters reflecting left ventricular functions, such as left ventricular end systolic pressure, left ventricular end diastolic pressure, isovolumic pressure (IP) and the maximal increasing/decreasing rate of left intraventricular pressure (±dp/dtmax), were also determined before and after MC. Left ventricular functions were determined either by two dimensional transthoracic echocardiography or by speckle tracking imaging for segmental abnormal ventricular wall motions. RESULTS: Heart rate, systolic pressure, diastolic pressure and mean arterial pressure decreased significantly but transiently, while central venous pressure markedly increased after MC. In contrast to significant changes in diastolic functions, there was no significant change in cardiac systolic functions after MC. The speckle tracking imaging demonstrated that strain values of different myocardial segment significantly decreased post impact, and that of the ventricular segment decreased from segment to segment. CONCLUSION: Speckle tracking imaging is useful and informative to assess myocardial regional dysfunctions post MC.

Coronary perforation in the drug-eluting stent era: incidence, risk factors, management and outcome: the UK experience.

AIMS: Coronary perforation during percutaneous coronary intervention (PCI) is associated with a high risk of mortality and morbidity. However there has been little data on perforation in the current era despite significant changes in PCI practice. We set out to identify incidence, risk factors and management strategies of coronary perforation in the current era. METHODS AND RESULTS: We performed a retrospective analysis of the Manchester Heart Centre PCI database from June 2004 to May 2008. Detailed analysis of all cases of suspected perforation was undertaken by case note and angiographic review. Demographic data was collected regarding all patients undergoing intervention. A total of 12,729 coronary lesions were treated in 7,903 patients over four years, during which drug-eluting stent (DES) uptake was 77%. The incidence of perforation was 0.56% (44/12,729). Perforation was associated with an inpatient mortality of 15.9% (7/44). Factors associated with perforation were female sex (p=0.003), increasing age (p<0.01), coronary calcification (p=0.003), use of a cutting balloon (p<0.001) or atheroablation (p<0.001), and treatment of a chronic total occlusion (p<0.01). Factors associated with death after perforation were non-elective procedure (p=0.036) and pericardial drain insertion (p<0.001). CONCLUSIONS: Despite treatment of more complex disease, the incidence of coronary perforation has not increased. Major perforations (Ellis class III) are associated with a high rate of emergency coronary artery bypass graft (CABG) and death. Endovascular treatments allow sealing of the perforation in most cases and deaths occur primarily as a result of cardiogenic shock due to occlusion of the culprit artery. Patient risk factors associated with perforation should be considered when planning or performing PCI.

Long-term functional and echocardiographic assessment after penetrating cardiac injury: 5-year follow-up results.

BACKGROUND: There is almost no data describing the long-term functional outcome of patients after penetrating cardiac injury. METHODS: A retrospective study at a Level I trauma center from 2000 to 2009. RESULTS: Sixty-three patients had penetrating cardiac injuries from 28 stabbings and 35 gunshots. Men comprised 89% (56) of the patients. Overall, there were 21 survivors (33%) and 42 died in the emergency room or perioperative period. The mean age did not significantly differ between survivors (36 years ± 12 years) compared with those who died (30 years ± 11 years; p=0.07). There was an increased chance of survival after being stabbed compared with being shot (17 patients vs. 4 patients; odds ratio=12; p=0.002). Thirteen (62%) had injuries to the right ventricle only. Three patients died during follow-up: one from lung cancer and two other patients died from myocardial infarctions, one 9 years later at the age of 45 years and the other 8 years later at the age of 55 years. The survivors had functional follow-up evaluations from 2 months to 114 months (median, 71; interquartile range, 34-92 months) and echocardiographic follow-up from 2 months to 107 months (median, 64; interquartile range, 31-84 months) after their injuries. Functionally, all patients were in NYHA class 1 status, except one patient in class II who was 54 years old and had a mild exertional limitation. The previously injured area could only be identified by echocardiogram in one patient who had a patch repair of a ventricular septal defect (VSD). The mean ejection fraction improved over time from a mean of 51% ± 8% in the immediate postoperative period to 60% ± 9% after a mean follow-up of 59 months (p=0.01). After surgery, 43% of patients had a mild to moderate pericardial effusion; however, the long-term follow-up studies showed that all these had resolved. Wall motion abnormalities occurred in 33% of patients in the immediate postoperative period and, again, all these resolved during long-term follow-up. CONCLUSIONS: Patients who survive penetrating cardiac injuries, without coronary arterial or valvular disruption, have an excellent long-term functional outcome with minimal subsequent cardiac morbidity related to the injury. Full physiologic recovery and normal cardiac function can be expected if the patient survives.

Transthoracic echocardiogram is a useful tool in the hemodynamic assessment of patients with chest trauma.

INTRODUCTION: The utility of transthoracic echocardiogram (TTE) in patients on the trauma service is not well defined. The aim of this study was to evaluate the frequency of abnormal echocardiographic findings that would aid in the assessment and management of cardiovascular hemodynamics in patients with chest trauma. METHODS: A retrospective analysis of all patients who had a TTE on the trauma service at a level 1 trauma center during a 12-month period was performed. RESULTS: There were 94 patients in the study. TTE was performed after cardiac surgery in 5 patients. One of the 5 patients with prior cardiac surgery was excluded from the study because of poor quality images, and each of the remaining 4 patients showed significant TTE abnormalities. Of the 89 patients without prior cardiac surgery, 38 (43%) had significant TTE findings although 32 (84%) of them had no known history of cardiac abnormalities. A decreased left ventricular ejection fraction (<50%) was found in 18% of all patients, and half of them were hemodynamically unstable. Significant valvular regurgitation or stenosis was found in 31 patients, pulmonary hypertension in 25 patients, left ventricular wall motion abnormalities in 12 patients and pericardial effusion in 11 patients. CONCLUSION: Significant echocardiographic abnormalities are detected by TTE in patients with chest trauma. Such findings can be used in the hemodynamic assessment and management of unstable patients during their hospitalization and in planning long-term follow-up and management of these patients after discharge from the hospital.

FAST (focused assessment with sonography in trauma) accurate for cardiac and intraperitoneal injury in penetrating anterior chest trauma.

OBJECTIVE: To evaluate the FAST (focused assessment with sonography in trauma) examination for determining traumatic pericardial effusion and intraperitoneal fluid indicative of injury in patients with penetrating anterior chest trauma. METHODS: An observational prospective study was conducted over a 30-month period at an urban level I trauma center. FAST was performed in the emergency department by emergency physicians and trauma surgeons. FAST results were recorded before review of patient outcome as determined by 1 or more of the following: thoracotomy, laparotomy, pericardial window, cardiologic echocardiography, diagnostic peritoneal lavage, computed tomography, and serial examinations. RESULTS: FAST was undertaken in 32 patients with penetrating anterior chest trauma: 20 (65%) had stab wounds, and 12 (35%) had gunshot wounds. Sensitivity of FAST for cardiac injury (n = 8) in patients with pericardial effusion was 100% (95% confidence interval, 63.1%-100%); specificity was 100% (95% confidence interval, 85.8%-100%). The presence of pericardial effusion determined by FAST correlated with the need for thoracotomy in 7 (87.5%) of 8 patients (95% confidence interval, 47.3%-99.7%). One patient with a pericardial blood clot on cardiologic echocardiography was treated nonsurgically. FAST had 100% sensitivity for intraperitoneal injury (95% confidence interval, 63.1%-100%) in 8 patients with views indicating intraperitoneal fluid but without pericardial effusion, again with no false-positive results, giving a specificity of 100% (95% confidence interval, 85.8%-100%). This prompted necessary laparotomy in all 8. CONCLUSIONS: In this series of patients with penetrating anterior chest trauma, the FAST examination was sensitive and specific in the determination of both traumatic pericardial effusion and intraperitoneal fluid indicative of injury, thus effectively guiding emergent surgical decision making.

Role of transesophageal echocardiography in the assessment of patients with blunt chest trauma: correlation of echocardiographic findings with the electrocardiogram and creatine kinase monoclonal antibody measurements.

OBJECTIVES: This study was designed to evaluate the usefulness of transesophogeal echocardiography (TEE) for detecting cardiac damage after blunt chest trauma (BCT). BACKGROUND: Multiple methods have been used to detect cardiac damage after a BCT, but none has been demonstrated to be sensitive, specific, and feasible enough. METHODS: This multicenter prospective trial was designed to evaluate the usefulness of TEE in the assessment of patients with BCT and to compare the TEE findings with those provided by the electrocardiogram (ECG) and cardiac isoenzymes assay. One hundred seventeen consecutive patients with a significant BCT were enrolled. A TEE was performed in each patient. Serial ECGs and plasma profiles of creatine kinase (CK) and CK-monoclonal antibody (MB) were obtained. RESULTS: Sixty-six (56%) patients had pathologic findings in the TEE attributed to the BCT (group A). In the remaining 51 (44%) patients the TEE was normal (group B). An abnormal ECG was more frequent in group A (59% vs 24%; p < 0.001), and the serum CK-MB peak level was also higher in group A (174 +/- 30 U/L vs 93 +/- 21 U/L; p = 0.05). Relative to pathologic TEE findings, the sensitivity and specificity of an abnormal ECG were 59% and 73% and of high CK-MB with CK-MB/CK > 5% were 64% and 52%, respectively. CONCLUSIONS: We conclude that TEE can be routinely and safely performed for diagnosing cardiac injuries after a BCT and plays an important role in the evaluation and treatment of these patients. EGG and CK-MB assay are not good methods for detecting cardiac damage in this setting.

Echocardiography in the emergency room: is it feasible, beneficial, and cost-effective?

Echocardiography in the emergency room presents exciting practice possibilities that can facilitate prompt and reliable diagnostic evaluations in patients with suspected cardiovascular emergencies. Echocardiography has the diagnostic potentials to evaluate the entire spectrum of cardiovascular abnormalities short of delineating coronary anatomy and evaluation of the conduction system. By reliably assessing the global and regional function, visualizing the cardiovascular structures from multiple tomographic planes, and quantitating hemodynamic abnormalities, echocardiography should be able to assist emergency room physician's evaluation and triage of the patients with chest pain syndrome, unexplained dyspnea, hypotension, shock, chest trauma, and cardiac arrest, whereby hopefully minimizing the unnecessary admission to the hospital and facilitating inhospital evaluation of the admitted patients with echocardiographic information. However, the optimal echocardiography practice in the emergency room requires well trained sonographers and echocardiographers who can respond to the clinical needs at anytime. Whether an emergency room physician can perform and interpret echocardiographic examinations satisfactorily will depend on his/her level of training and continuing education in this area. Currently, there is no established guideline for performing echocardiography in the emergency room. Further clinical investigations are necessary to define the most optimal and economical utilization of this versatile imaging and hemodynamic diagnostic modality in the emergency room.

[Value of transesophageal echocardiography in the assessment of blunt chest trauma: correlation with electrocardiogram, heart enzymes, and transthoracic echocardiogram]. / Valor da ecocardiografia transesofágica na avaliação de doentes com traumatismo torácico fechado: correlação com o electrocardiograma, enzimas cardíacas e ecocardiograma transtorácico.

OBJECTIVE: To asses the feasibility, usefulness and clinical rentability of the transesophageal echocardiography (TEE) in the evaluation of patients suffering a severe blunt chest trauma as well as to correlate the TEE findings with those provided by the conventional electrocardiogram (ECG), cardiac isoenzymes assay and transthoracic echocardiography (TTE). DESIGN: Prospective study using ECG, blood cardiac enzymes assay, TTE and TEE. SETTING: Intensive care unit of a general hospital. PATIENTS: We studied 34 patients admitted with blunt chest trauma and suspected cardiac contusion in spite of the existence of other traumatic injuries in some of them. There were 23 (67.6%) males and 11 females, with a mean age of 37.1 +/- 19.4 years (range: 16-69 years). MATERIAL AND METHODS: Patients with a previous history of cardiovascular or chronic pulmonary disease, cardiac arrest upon admission or positive cocaine or amphetamine levels in the urine were excluded from the study. Suspected cardiac contusion was established by clinical data, electrocardiographic findings, enzymes blood values (CPK-total and MB-fraction) and TTE findings. Additionally, a TEE was performed in each patient. Patients were stratified into two groups according to the TEE findings: Group A patients had signs compatible with cardiac contusion and in Group B patients there was a lack of evidence to substantiate this diagnosis. Those tests were evaluated in respect to their accuracy in the diagnosis of cardiac contusion when compared to transesophageal echocardiography and TEE findings were compared, whenever possible, to surgical or necropsic findings. RESULTS: We found TEE signs of cardiac injury in 22 (64.7%) patients and a wide spectrum of traumatic cardiac abnormalities were identified. TEE signs of ventricular injury were found in 15 pts of Group A (68.2%) being the right ventricle the most frequent affected. There were also two cases of mitral leaflet rupture, one case of tricuspid valve prolapse (with severe tricuspid regurgitation and associated with right ventricle wall motion abnormalities) and seven cases of pericardial effusion as well as one case of thoracic aortic dissection. In every patient submitted to cardiothoracic surgery or necropsy the TEE findings were confirmed. TEE provided significant information, sometimes crucial, to the patient evaluation and management, it was performed without any difficulty and it doesn't carried out any related complication. TTE was technically suboptimal in 53% and fail to demonstrate many cases of cardiac contusion and the thoracic aorta lesion, being the number of cardiovascular injuries demonstrated by TEE significantly higher (p = 0.029). No statistically significant difference was found between the number of patients with either an abnormal ECG or high values of CPK-MB in each group. Neither clinical findings, cardiac enzymes values, serial ECG's nor TTE predicted all the patients who had traumatic cardiac injury and those would subsequently developed complications related to cardiac contusion. CONCLUSIONS: A severe blunt chest trauma frequently results in cardiac injury. The ECG and the CPK-MB measurements appears both to be fairly sensitive and specific tests in the cardiac contusion diagnosis. TTE has shown to have important limitations in these patients, thus not allowing neither a complete echo evaluation nor a reliable one. TEE plays an important role in the evaluation and management of this type of patients providing rapid diagnostic information and being of high value in the rule out cardiac contusion as well as in the establishment of a specific diagnosis of cardiac and/or thoracic aorta injuries with a consequent better assessment and treatment strategy in these patients.

Accurate placement of central venous catheters: a prospective, randomized, multicenter trial.

OBJECTIVES: a) To define the frequency of dangerous (intracardiac) central venous catheter placement in a multicenter study of large community hospital intensive care units (ICUs) and to evaluate physician responses to this finding. b) To validate right atrial electrocardiography as a technique to assure adherence with recent Food and Drug Administration (FDA) guidelines regarding the location of central venous catheter tips. c) To conduct a literature review of vascular cannulation and its associated potentially lethal complications. DESIGN: Prospective, randomized, blinded, multicenter study. SETTING: Multidisciplinary ICUs in five large community teaching hospitals. PATIENTS: Consecutive patients (n = 112) who required a central venous catheter by either internal jugular vein or subclavian vein at four separate hospitals were assessed using 30-cm catheters. Consecutive patients (n = 50) in a fifth hospital who subsequently required a central venous catheter via the internal jugular vein or subclavian vein route were prospectively randomized to receive a 20-cm central venous catheter with either conventional surface-landmark guidance, or with the right atrial electrocardiography-guided technique. MAIN OUTCOME MEASURES: a) Occurrence rate of malpositioned central venous catheters. b) Ability of right atrial electrocardiography to aid in the accurate placement of central venous catheters. RESULTS: a) Using conventional placement techniques with a 30-cm catheter, 53 (47%) of 112 initial central venous catheter placements resulted in location of the catheter tip within the heart. Catheter tips were not repositioned to locations outside the right atrium after this finding was identified on initial post-procedure films. b) Using the right atrial electrocardiography technique to place 20-cm central venous catheters resulted in no catheter tip locations within the heart (0/25) vs. 14 (56%) of 25 (p < .0001) intracardiac placements using conventional techniques. c) The literature suggests that serious mechanical complications of central venous catheterization, although uncommon, are associated with a high mortality rate. Deaths are associated with intracardiac placement. CONCLUSIONS: a) The FDA guidelines regarding catheter tip location (catheter tip should not be in the right atrium) have not been widely publicized. b) The average safe insertion depth for a central venous catheter from the left or right internal jugular vein or subclavian vein is 16.5 cm for the majority of adult patients; a central venous catheter should not be routinely inserted to a depth of > 20 cm. Catheters longer than this size are rarely needed, and potentially dangerous. Catheter tip location is important to document following central venous catheter insertion. Thirty-centimeter central venous catheters should not be used when accessing the central circulation via internal jugular or subclavian veins. c) Right atrial electrocardiography is a technique that assures initial tip position outside the heart in accordance with FDA guidelines. This technique would virtually eliminate the major risk of death (i.e., cardiac perforation) associated with this procedure. d) Recently available, 15- and 16-cm central venous catheters have significant potential to minimize intracardiac placement of central venous catheters by either the internal jugular or subclavian vein route and may become the standard of care.