Survey of hospital practitioners: common understanding of cardiopulmonary resuscitation definition and outcomes.

BACKGROUND: Cardiopulmonary resuscitation (CPR) is internationally defined as chest compressions and rescue breaths, and is a subset of resuscitation. First used for out-of-hospital cardiac arrest, CPR is now frequently used for in-hospital cardiac arrest (IHCA) with different causes and outcomes. AIMS: This paper aims to describe clinical understanding of the role of in-hospital CPR and perceived outcomes for IHCA. METHODS: An online survey of a secondary care staff involved in resuscitation was conducted, focussing on definitions of CPR, features of do-not-attempt-CPR conversations with patients and clinical case scenarios. Data were analysed using a simple descriptive approach. RESULTS: Of 652 responses, 500 were complete and used for analysis. Two hundred eleven respondents were senior medical staff covering acute medical disciplines. Ninety-one percent of respondents agreed or strongly agreed that defibrillation is part of CPR, and 96% believed CPR for IHCA included defibrillation. Responses to clinical scenarios were dissonant, with nearly half of respondents demonstrating a pattern of underestimating survival and subsequently showing a desire to offer CPR in similar scenarios with poor outcomes. This was unaffected by seniority and level of resuscitation training. CONCLUSIONS: The common use of CPR in hospital reflects the broader definition of resuscitation. Recapturing the CPR definition for clinicians and patients as only chest compressions and rescue breaths may allow clinicians to better discuss individualised resuscitation care to aide meaningful shared decision-making around patient deterioration. This may involve reframing current in-hospital algorithms and uncoupling CPR from wider resuscitative measures.

Rethinking resuscitation: moving the goals.

Cardiopulmonary resuscitation (CPR) techniques have developed remarkably since first described. CPR is now both a default treatment and a public expectation. However, anticipated outcomes are not matched by reality. The differences between in- and out-of-hospital cardiac arrests are often not recognised and almost never taught. 'Do Not Resuscitate' orders developed to provide the ability to opt-out of this treatment. Nevertheless, CPR is still inappropriately used in settings where reversibility and likelihood of benefit are not meaningfully considered or discussed with the patient. Further, treatment escalation is a continuum, so resuscitation orders present a false dichotomy of 'do' or 'do not' resuscitate. Asking patients about their goals, and only offering treatments aligned with those goals, allows consideration of the burden of treatment and the likelihood of success. Shared decision models improve communication and patient autonomy. Tools are available to help clinicians with the difficult conversation and document the outcomes. Now, in both our training and practice, it is time to move beyond the stark and often irrelevant choice between CPR and 'Not for Resuscitation'.

Normal values of regional and global myocardial wall motion in young and elderly individuals using navigator gated tissue phase mapping.

The purpose of this study was to evaluate normal values for regional and global myocardial wall motion parameters in young and elderly individuals, as detected by navigator gated high temporal resolution tissue phase mapping. Radial, longitudinal and circumferential ventricular wall motion, as well as ventricular torsion and longitudinal strain rates, were assessed in two age groups of volunteers, 23 ± 3 (n = 14) and 66 ± 7 years old (n = 9), respectively. All subjects were healthy, non-smokers without known cardiac disease. An increased global left ventricular (LV) torsion rate (peak systolic torsion rate 20.6 ± 2.0 versus 14.5 ± 1.0°/s/cm, peak diastolic torsion rate -25.2 ± 1.8 versus -14.1 ± 1.3°/s/cm) and a decrease in longitudinal LV motion (peak systolic values at mid-ventricle 5.9 ± 0.5 versus 8.5 ± 0.8 cm/s, peak diastolic values -10.7 ± 0.7 versus -15.2 ± 0.9 cm/s) in the older age group were the most prominent findings. Lower peak diastolic radial velocities with a longer time-to-peak values, most pronounced at the apex, are consistent with reduced diastolic function with ageing. Lower peak clockwise and counter-clockwise velocities at all LV levels revealed limitations in resting LV rotational motions in the older group. Significant changes in the undulating pattern of the rotational motions of the left ventricle were also observed. The results demonstrate distinct changes in regional and global myocardial wall motion in elderly individuals. Increased LV torsion rate and reduced LV longitudinal motion were particularly prominent in the older group. These parameters may have a role in the assessment of global LV contractility and help differentiate age-related changes from cardiac disease.

Patients with syndrome X have normal transmural myocardial perfusion and oxygenation: a 3-T cardiovascular magnetic resonance imaging study.

BACKGROUND: The pathophysiology of chest pain in patients with cardiac syndrome X remains controversial. Advances in perfusion imaging with cardiovascular magnetic resonance (CMR) now enable absolute quantification of regional myocardial blood flow (MBF). Furthermore, blood oxygen level-dependent (BOLD) or oxygenation-sensitive CMR provides the unprecedented capability to assess regional myocardial oxygenation. We hypothesized that the combined assessment of regional perfusion and oxygenation with CMR could clarify whether patients with syndrome X show evidence of myocardial ischemia (reduced perfusion and oxygenation) during vasodilator stress compared with normal volunteers. METHODS AND RESULTS: Eighteen patients with syndrome X (chest pain, abnormal exercise treadmill test, normal coronary angiogram without other causes of microvascular dysfunction) and 14 controls underwent CMR scanning at 3 T. Myocardial function, scar, perfusion (2-3 short-axis slices), and oxygenation were assessed. Absolute MBF was measured during adenosine stress (140 µg/kg per minute) and at rest by model-independent deconvolution. For oxygenation, using a T2-prepared BOLD sequence, signal intensity was measured at adenosine stress and rest in the slice matched to the midventricular slice of the perfusion scan. There were no significant differences in MBF at stress (2.35 versus 2.37 mL/min per gram; P=0.91), BOLD signal change (17.3% versus 17.09%; P=0.91), and coronary flow reserve measurements (2.63 versus 2.53; P=0.60) in patients with syndrome X and controls, respectively. Oxygenation and perfusion measurements per coronary territory were also similar between the 2 groups. More patients with syndrome X (17/18 [94%]) developed chest pain during adenosine stress than controls (6/14 [43%]; P=0.004). CONCLUSIONS: Patients with syndrome X show greater sensitivity to chest pain compared with controls but no evidence of deoxygenation or hypoperfusion during vasodilatory stress.

Chasing the reflected wave back into the heart: a new hypothesis while the jury is still out.

BACKGROUND: Arterial stiffness directly influences cardiac function and is independently associated with cardiovascular risk. However, the influence of the aortic reflected pulse pressure wave on left ventricular function has not been well characterized. The aim of this study was to obtain detailed information on regional ventricular wall motion patterns corresponding to the propagation of the reflected aortic wave on ventricular segments. METHODS: Left ventricular wall motion was investigated in a group of healthy volunteers (n = 14, age 23 ± 3 years), using cardiac magnetic resonance navigator-gated tissue phase mapping. The left ventricle was divided into 16 segments and regional wall motion was studied in high temporal detail. RESULTS: Corresponding to the expected timing of the reflected aortic wave reaching the left ventricle, a characteristic "notch" of regional myocardial motion was seen in all radial, circumferential, and longitudinal velocity graphs. This notch was particularly prominent in septal segments adjacent to the left ventricular outflow tract on radial velocity graphs and in anterior and posterior left ventricular segments on circumferential velocity graphs. Similarly, longitudinal velocity graphs demonstrated a brief deceleration in the upward recoil motion of the entire ventricle at the beginning of diastole. CONCLUSION: These results provide new insights into the possible influence of the reflected aortic waves on ventricular segments. Although the association with the reflected wave appears to us to be unambiguous, it represents a novel research concept, and further studies enabling the actual recording of the pulse wave are required.

Details of left ventricular remodeling and the mechanism of paradoxical ventricular septal motion after coronary artery bypass graft surgery.

OBJECTIVE: The purpose of this study was to obtain new details of three-dimensional left ventricular wall motion related to ventricular remodeling in patients undergoing coronary artery bypass graft (CABG) surgery. METHODS: Cardiac-gated, phase-contrast measurements using navigator-gated, high temporal resolution, tissue phase mapping were obtained on 19 patients (66 ± 7 years old) before and after CABG. Left ventricular motion patterns and myocardial velocities were recorded for radial, circumferential and longitudinal motion. Radial, circumferential and longitudinal velocity curves were obtained separately for 16 ventricular segments. Ventricular torsion rate and longitudinal strain rate were also derived pre- and post-surgery. RESULTS: After CABG, there was a significant improvement in apical contraction, with an apparent paradoxical decrease in the radial inward motion of the septal segments at the left ventricular base. Despite improved ventricular contractility during systole, peak longitudinal and rotational velocities decreased or showed no significant changes. An altered pattern of rotational motion with decreased initial counter-clockwise rotation at the beginning of systole and subsequent lower amplitude of reversed motions in diastole was also noted in most left ventricular segments. Lower peak clockwise rotational velocities were recorded in the basal anteroseptal segment with relatively higher values in the rest of the basal segments. CONCLUSION: Our results suggest that post-operative changes after CABG are limiting ventricular rotational and longitudinal motions, despite an increase in ventricular contractility due to revascularization. At the ventricular base, the restrained rotational motion of basal anteroseptal segment, located proximally to the right ventricular insertion, and higher rotational velocities of the rest of the segments are pushing the septum toward the right ventricle during ventricular twisting. At the ventricular apex, the restrain in rotational motion caused by post-operative adhesions is affecting all apical segments due to a much smaller left ventricular diameter at this level. The rotating apex and the apical septum are similarly displaced toward the right ventricle during ventricular twisting.

Utility of cardiac biomarkers for the diagnosis of type V myocardial infarction after coronary artery bypass grafting: insights from serial cardiac MRI.

OBJECTIVES: To examine, using cardiac magnetic resonance (CMR), the utility of cardiac biomarkers for the determination of myocyte necrosis and function after coronary artery bypass grafting (CABG), and to test the recently updated guidelines for the diagnosis of postoperative myocardial infarction (type V MI). METHODS AND RESULTS: Forty patients included in a single-centre randomised trial of two surgical techniques for performing CABG underwent serial assessment with CMR biochemical markers. Cine and delayed enhancement CMR (DE-CMR) for assessment of left ventricular (LV) function and irreversible myocyte necrosis was performed and levels of troponin I (TnI) and creatine kinase-MB isoform (CK-MB) were determined. The area under the curve for TnI strongly correlated with the mass of new myocyte necrosis as assessed by DE-CMR (r = 0.83, p<0.001), compared with CK-MB (r=0.39, p=0.06). Furthermore, routine assessment of TnI alone at 24 h (> 6.6 µg/l) predicted type V MI on DE-CMR with a sensitivity of 88% and specificity of 97%, whereas CK-MB predicted type V MI with a sensitivity of 75% and specificity of 87%. CONCLUSIONS: Biomarkers alone (TnI), at an appropriate threshold appear robust for the detection of type V MI, independently of supplementary evidence, as suggested by the ESC/ACCF/AHA/WHF criteria. Clinical trial registration information The study is listed on the Current Controlled Trials Registry: ISRCTN41388968. URL: http://www.controlled-trials.com.

Prediction of global left ventricular functional recovery in patients with heart failure undergoing surgical revascularisation, based on late gadolinium enhancement cardiovascular magnetic resonance.

BACKGROUND: The new gold standard for myocardial viability assessment is late gadolinium enhancement-cardiovascular magnetic resonance (LGE-CMR); this technique has demonstrated that the transmural extent of scar predicts segmental functional recovery. We now asked how the number of viable and number of viable+normal, segments predicted recovery of global left ventricular (LV) function in patients undergoing CABG. Finally, we examined which segmental transmural threshold of scarring best predicted global LV recovery. METHODS AND RESULTS: Fifty patients with reduced LV ejection fraction (EF) referred for CABG were recruited, and 33 included in this analysis. Patients underwent CMR to assess LV function and viability pre-operatively at 6 days and 6 months. Mean LVEF 38% ± 11, which improved to 43% ± 12 after surgery. 21/33 patients improved EF by ≥3% (EF before 38% ± 13, after 47% ± 13), 12/33 did not (EF before 39% ± 6, after 37% ± 8). The only independent predictor for global functional recovery after revascularisation was the number of viable+normal segments: Based on a segmental transmural viability cutoff of <50%, ROC analysis demonstrated ≥10 viable+normal segments predicted ≥3% improvement in LVEF with a sensitivity of 95% and specificity of 75% (AUC = 0.9, p < 0.001). Transmural viability cutoffs of <25 and <75% and a cutoff of ≥4 viable segments were less useful predictors of global LV recovery. CONCLUSIONS: Based on a 50% transmural viability cutoff, patients with ≥10 viable+normal segments improve global LV function post revascularisation, while patients with fewer such segments do not. LGE-CMR is a simple and powerful tool for identifying which patients with impaired LV function will benefit from CABG. TRIAL REGISTRATION: Research Ethics Committee Unique Identifier: NRES:05/Q1603/42. The study is listed on the Current Controlled Trials Registry: ISRCTN41388968.URL: http://www.controlled-trials.com.

Adenosine stress myocardial contrast echocardiography for the detection of coronary artery disease: a comparison with coronary angiography and cardiac magnetic resonance.

OBJECTIVES: To evaluate the accuracy of adenosine myocardial contrast echocardiography (MCE) in diagnosing coronary artery disease (CAD). BACKGROUND: Adenosine stress echocardiography is not routinely used in the assessment of CAD. Since ultrasound microbubble contrast agents enable improved wall motion analysis and simultaneous assessment of myocardial perfusion, we sought to evaluate the diagnostic performance of combined wall motion/perfusion imaging with adenosine MCE in patients with suspected CAD. We evaluated the accuracy of adenosine MCE in identifying 1) the presence of anatomic disease, as defined by X-ray angiography, and 2) the functional significance of CAD, as determined by high field-strength (3-T), multiparametric cardiac magnetic resonance (CMR) imaging. METHODS: Sixty-five patients with suspected CAD were studied before angiography with MCE and CMR, at stress (140 µg/kg/min intravenous adenosine) and at rest. For MCE, 2-, 3- and 4-chamber long-axis images were acquired during intravenous sulfur hexafluoride infusion. For CMR, short-axis first-pass perfusion and delayed enhancement images were acquired following intravenous gadolinium-diethylenetriaminepentaacetic acid bolus injections (0.05 mmol/kg). Quantitative coronary angiography served as a reference standard for anatomic disease (significant CAD defined as ≥ 50% reference diameter in vessels with diameter ≥ 2 mm). RESULTS: Compared with X-ray angiography, MCE provided diagnostic accuracy of 82%, sensitivity of 85%, and specificity of 76% for detecting significant coronary stenosis. Disease location was also identified with reasonable accuracy (diagnostic accuracy 81% for left anterior descending disease, 77% for left circumflex artery disease, and 84% for right coronary artery disease). With CMR as the reference standard for functional assessment, MCE provided diagnostic accuracy of 79%, sensitivity of 85%, and specificity of 74%. Interobserver agreement for MCE was 79% (95% confidence interval: 67% to 88%). CONCLUSIONS: Adenosine MCE achieved favorable diagnostic performance in identifying the presence and functional significance of coronary stenosis. Adenosine MCE may be useful in the clinical setting for evaluating patients with suspected CAD.

Tolerance and safety of adenosine stress perfusion cardiovascular magnetic resonance imaging in patients with severe coronary artery disease.

We sought to assess the tolerance and safety of adenosine-stress cardiovascular magnetic resonance (CMR) perfusion imaging in patients with coronary artery disease (CAD). We retrospectively examined all adenosine CMR perfusion scans performed in our centre in patients with known or suspected (CAD) and normal volunteers at either 1.5 or 3 T. All subjects were initially screened for contraindications to adenosine. The dose of adenosine infused was 140 microg/kg/min. Significant CAD was defined angiographically as the presence of at least one stenosis of >50% diameter. Data were collected from 351 consecutive subjects (mean age 62 +/- 11 years, range 25-85 years-245 men). Of the 351 subjects, 305 had a coronary angiogram, the remaining 46 subjects were normal volunteers studied for research protocols. In total, 233 subjects (76%) were found to have significant CAD of whom 128 had multi-vessel disease. There were no deaths, myocardial infarctions, or episodes of bronchospasm during the CMR study. Transient 2nd (Mobitz II) or 3rd-degree atrioventricular (AV) block occurred in 27 patients (8%). There were no sustained episodes of advanced AV block. Transient chest pain was the most common side effect (199 subjects-57%). The use of intravenous adenosine in CMR perfusion imaging is safe and well-tolerated, even in patients with severe CAD. Where a careful screening policy for contraindications to adenosine is followed, serious adverse events in the CMR scanner are relatively rare and symptoms resolve following termination of the infusion, without the need for aminophylline.

Left ventricular lipomatous metaplasia following myocardial infarction.

We present 3 cases of left ventricular lipomatous metaplasia after myocardial infarction evaluated with cardiovascular magnetic resonance (CMR). Delayed enhancement CMR alone cannot differentiate lipomatous metaplasia from scar. T1-weighted images with and without fat suppression are needed to identify this condition. The aetiology, pathophysiology, and possible clinical significance of lipomatous metaplasia in infarcted myocardium are still unknown. The multi-parametric capabilities of CMR make it the ideal modality to identify non-invasively, and without exposure to radiation, individuals with lipomatous metaplasia.

A randomized trial of on-pump beating heart and conventional cardioplegic arrest in coronary artery bypass surgery patients with impaired left ventricular function using cardiac magnetic resonance imaging and biochemical markers.

BACKGROUND: Beating heart coronary artery bypass grafting (CABG) improves early postoperative cardiac function in patients with normal ventricular function, but its effect in patients with impaired function is uncertain. We compared a novel hybrid technique of on-pump beating heart CABG (ONBEAT) with conventional on-pump CABG (ONSTOP) in patients with impaired ventricular function. METHODS AND RESULTS: In a single-center randomized trial, 50 patients with impaired ventricular function were randomly assigned to ONBEAT or ONSTOP. Patients underwent cardiac magnetic resonance imaging for function and delayed hyperenhancement early and later after surgery. Serial assessment of biochemical markers was also undertaken. Preoperative characteristics were well matched; cardiac index was 2.85+/-0.53 (ONBEAT) and 2.62+/-0.59 L x min(-1) x m(-2) (ONSTOP). Early after surgery, there was a trend toward a greater reduction in end-systolic volume index in ONSTOP patients versus ONBEAT (-9+/-8 versus -4+/-11 mL x m(-2); P=0.06). The changes were sustained and significant at 6 months (-14+/-18 versus -2+/-19 mL x m(-2); P=0.04). Furthermore, the incidence of new hyperenhancement at 6 days was higher in ONBEAT patients (P=0.05), with 6 of 17 (35%) sustaining 8.2+/-5.2 g of new hyperenhancement each versus 2 of 23 (9%) in the ONSTOP group, each with 9.8+/-9.0 g (P=0.86). Finally, median area under the curve for troponin was higher in ONBEAT at 461 (interquartile range, 226 to 1141) microg/L versus 160 (interquartile range, 98 to 357) microg/L for ONSTOP (P=0.002). CONCLUSIONS: The incidence of new irreversible myocardial injury was significantly higher in ONBEAT than in ONSTOP patients. Furthermore, at 6 months, only ONSTOP patients demonstrated an improvement in ventricular geometry. The most likely mechanism is inadequate coronary perfusion to distal myocardial territories in patients with severe proximal coronary disease.

Effects of off-pump versus on-pump coronary artery bypass grafting on early and late right ventricular function.

BACKGROUND: Off-pump CABG (OPCABG) results in better preservation of left ventricular function in the perioperative period than conventional on-pump CABG (ONCABG); however, evidence is conflicting as to the effect of OPCABG and ONCABG on right ventricular (RV) function, possibly because of the complexity involved in measuring this. METHODS AND RESULTS: In a single-center randomized pilot study, 60 patients with normal left ventricular function undergoing CABG were randomly assigned to OPCABG or ONCABG. Patients underwent cardiac magnetic resonance imagine for assessment of RV function preoperatively, early postoperatively, and at 6 months after surgery. Fifty-one patients completed the first 2 scans, and 47 completed all 3 scans. Preoperative characteristics and RV function did not differ significantly between the 2 groups (mean+/-SD): RV stroke volume index was 49+/-10 mL/m(2) for OPCABG and 49+/-16 mL/m(2) for ONCABG. After surgery, RV stroke volume index fell to 36+/-7 mL/m(2) in the OPCABG group and 39+/-11 mL/m(2) in the ONCABG group, but this did not differ significantly between the 2 groups (P=0.41). All markers of RV function recovered to preoperative levels by 6 months, with no long-term difference between the surgical techniques. CONCLUSIONS: RV function is impaired early after surgery but recovers by 6 months. The changes were similar in both the OPCABG and ONCABG groups.

Cardiovascular magnetic resonance perfusion imaging at 3-tesla for the detection of coronary artery disease: a comparison with 1.5-tesla.

OBJECTIVES: This study was designed to establish the diagnostic accuracy of cardiovascular magnetic resonance (CMR) perfusion imaging at 3-Tesla (T) in suspected coronary artery disease (CAD). BACKGROUND: Myocardial perfusion imaging is considered one of the most compelling applications for CMR at 3-T. The 3-T systems provide increased signal-to-noise ratio and contrast enhancement (compared with 1.5-T), which can potentially improve spatial resolution and image quality. METHODS: Sixty-one patients (age 64 +/- 8 years) referred for elective diagnostic coronary angiography (CA) for investigation of exertional chest pain were studied (before angiogram) with first-pass perfusion CMR at both 1.5- and 3-T and at stress (140 microg/kg/min intravenous adenosine, Adenoscan, Sanofi-Synthelabo, Guildford, United Kingdom) and rest. Four short-axis images were acquired during every heartbeat using a saturation recovery fast-gradient echo sequence and 0.04 mmol/kg Gd-DTPA bolus injection. Quantitative CA served as the reference standard. Perfusion deficits were interpreted visually by 2 blinded observers. We defined CAD angiographically as the presence of > or =1 stenosis of > or =50% diameter in any of the main epicardial coronary arteries or their branches with a diameter of > or =2 mm. RESULTS: The prevalence of CAD was 66%. All perfusion images were found to be visually interpretable for diagnosis. We found that 3-T CMR perfusion imaging provided a higher diagnostic accuracy (90% vs. 82%), sensitivity (98% vs. 90%), specificity (76% vs. 67%), positive predictive value (89% vs. 84%), and negative predictive value (94% vs. 78%) for detection of significant coronary stenoses compared with 1.5-T. The diagnostic performance of 3-T perfusion imaging was significantly greater than that of 1.5-T in identifying both single-vessel disease (area under receiver-operator characteristic [ROC] curve: 0.89 +/- 0.05 vs. 0.70 +/- 0.08; p < 0.05) and multivessel disease (area under ROC curve: 0.95 +/- 0.03 vs. 0.82 +/- 0.06; p < 0.05). There was no difference between field strengths for the overall detection of coronary disease (area under ROC curve: 0.87 +/- 0.05 vs. 0.78 +/- 0.06; p = 0.23). CONCLUSIONS: Our study showed that 3-T CMR perfusion imaging is superior to 1.5-T for prediction of significant single- and multi-vessel coronary disease, and 3-T may become the preferred CMR field strength for myocardial perfusion assessment in clinical practice.