Coronary angiographic findings for out-of-hospital cardiac arrest survivors presenting with nonshockable rhythms and no ST elevation post resuscitation.

BACKGROUND: Recent guidelines suggest that coronary angiography (CAG) should be considered for out-of-hospital cardiac arrest (OHCA) survivors, including those without ST elevation (STE) and without shockable rhythms. However, there is no prospective data to support CAG for survivors with nonshockable rhythms and no STE post resuscitation. METHODS: This was a re-analysis of the PEARL study (randomized OHCA survivors without STE to early CAG versus not). Patients were subdivided by initial rhythm as nonshockable (Nsh) vs shockable (Sh). The primary outcome was coronary angiographic evidence of acute culprit lesion, with secondary outcomes being survival to hospital discharge and neurological recovery. RESULTS: The PEARL study included 99 patients with OHCA from a presumed cardiac etiology, 24 with nonshockable and 75 with shockable rhythms. There was no difference in the frequency of CAG between the two groups [71% (Nsh) and 75% (Sh); p = 0.79], presence of CAD [81% (Nsh) and 68% (sh); p = 0.37, or culprit lesions identified in each group [50% (Nsh) and 45% (Sh); p = 0.78. Nonshockable patients had worse discharge survival [33% (Nsh) vs 57% (Sh); p = 0.04] and those survived, had worse neurological recovery [30% (Nsh) vs 54% (Sh); p = 0.02] compared to shockable patients. CONCLUSIONS: OHCA survivors presenting with nonshockable rhythms and no STE post resuscitation had similar prevalence of culprit coronary lesions to those with shockable rhythms. CAG may be considered in patients with OHCA without STE regardless of initial presenting rhythm. There was no benefit of emergent CAG both in shockable and non-shockable rhythms.

Elevated troponin I level on admission is associated with adverse outcome of primary angioplasty in acute myocardial infarction.

BACKGROUND: In patients with acute myocardial infarction (AMI) undergoing thrombolytic therapy, an elevated troponin level on admission is associated with a lower reperfusion rate and a complicated clinical course. Whether an elevated troponin level on admission similarly predicts an adverse outcome in patients undergoing primary angioplasty is currently unknown and was investigated in the present study. METHODS AND RESULTS: Cardiac troponin I (cTnI) was determined on admission in 110 consecutive patients with AMI associated with ST-segment elevation or left bundle branch block who underwent primary angioplasty. Fifty-four patients (49%) had an elevated cTnI (>/=0.4 ng/mL) on admission. In patients with elevated cTnI, primary angioplasty was less likely to achieve TIMI 3 flow (as classified by the Thrombolysis in Myocardial Infarction trial) in univariate (76% versus 96%, P:=0.03) or in multivariate (odds ratio 0.1, 95% CI 0.02 to 0.54) analysis. Patients with elevated cTnI were more likely to develop congestive heart failure (23% versus 9%, P:<0.05) and death, heart failure, or shock (30% versus 9%, P:=0.006). Elevated cTnI remained a significant predictor of the composite end point after controlling for other clinical data that were available early in the course, including time to presentation and angiographic results (relative risk 5.2, 95% CI 1.03 to 26.3). During a follow-up of 426+/-50 days, elevated admission cTnI was a predictor of cardiac mortality (11% versus 0%, P:=0.012), adverse cardiac events (cardiac mortality or nonfatal reinfarction; 19% versus 5.4%, P:=0.04), and adverse cardiac events plus target vessel revascularization (32% versus 14%, P:=0.054). CONCLUSIONS: In patients with ST-segment elevation AMI, an elevated cTnI on admission is associated with an increased risk of primary angioplasty failure and a more complicated clinical course.

Mechanical ventilation may not be essential for initial cardiopulmonary resuscitation.

BACKGROUND: In a rodent model of cardiac arrest and resuscitation in which the inspired gas mixture was enriched with oxygen, resuscitability and survival were unaffected by positive pressure ventilation. In the present study, in a larger animal model, tidal volumes generated during precordial compression and with spontaneous gasping were quantitated. METHODS: Domestic pigs with an average weight of 34 kg were anesthetized with pentobarbital. Ventricular fibrillation (VF) was induced electrically. Precordial compression was begun after 4 min of untreated VF. Each of 22 animals received one of two interventions in conjunction with precordial compression: positive pressure ventilation with oxygen or oxygen supplied at the port of a tracheal tube at ambient pressure. After 8 min of precordial compression, defibrillation was attempted. RESULTS: Only very moderate increases in arterial PCO2 were documented during cardiopulmonary resuscitation in the absence of mechanical ventilation but arterial oxygen tension was consistently in excess of 100 mm Hg. Cardiac resuscitability and 48-h survival were approximately the same in animals maintained on inspired oxygen whether or not they were mechanically ventilated (7/11 or 8/11). In the absence of mechanical ventilation, precordial compression and spontaneous gasping yielded minute volumes that exceeded 5 L. CONCLUSION: Positive pressure mechanical ventilation did not improve resuscitability or postresuscitation outcome in this porcine model of cardiac arrest.

Subacute rupture of the left ventricular free wall after acute myocardial infarction. Three cases of long-term survival without emergency surgical repair.

Rupture of the left ventricular free wall after acute myocardial infarction (AMI) has been regarded as uniformly fatal unless emergency surgical repair is performed. Among 2,862 patients admitted with AMI to our ICU during the last 8 years, 107 patients developed rupture of the left ventricular free wall. Twenty-nine patients had a subacute course and three of them survived for prolonged periods without having to have emergency surgical repair. At the onset of rupture on day 1 through 7 after AMI, the three survivors developed sudden hypotension accompanied by a new pericardial effusion. They were initially managed with hemodynamic support. Two patients had elective open-heart surgery 2 to 3 months after AMI, whereas one patient did nt require surgery. All three survived 1 1/2 to 8 1/2 years after AMI. This report indicates that a small subset of patients with subacute ventricular free wall rupture has a benign course that may allow for prolonged survival without having to have emergency surgical repair.

Diagnosis and treatment of shock due to massive pulmonary embolism: approach with transesophageal echocardiography and intrapulmonary thrombolysis.

STUDY OBJECTIVES: To evaluate the diagnostic value of transesophageal echocardiography (TEE) as an initial diagnostic tool in shocked patients. The second objective was to study therapeutic impact of intrapulmonary thrombolysis in patients with diagnosed massive pulmonary embolism. DESIGN: Prospective observational study. SETTING: Medical ICU in 800-bed general hospital. PATIENTS: Twenty-four consecutive patients with unexplained shock and distended jugular veins. MEASUREMENTS AND MAIN RESULTS: In 18 patients, right ventricular dilatation with global or segmental hypokinesis was documented. In addition, central pulmonary thromboemboli (12 patients), reduced contrast flow in right pulmonary artery (one patient), and right ventricular free wall akinesis (one patient) were found. No additional echocardiographic findings were apparent in four patients. According to pulmonary scintigraphy or autopsy, sensitivity of TEE for diagnosis of massive pulmonary embolism (MPE) in patients with right ventricular dilatation was 92% and specificity was 100%. In patients without right ventricular dilatation, left ventricular dysfunction (four patients) or cardiac tamponade (two patients) was confirmed. Intrapulmonary thrombolysis was evaluated in 11 of 13 patients with MPE. Two patients died prior to attempted thrombolysis. Three patients received streptokinase and eight received urokinase. Twenty-four hours after beginning of treatment, total pulmonary resistance index significantly decreased for 59% and mean pulmonary artery pressure for 31%. Cardiac index increased for 74%. Nine of 11 patients receiving thrombolysis survived to hospital discharge. CONCLUSION: Bedside TEE is a valuable tool for diagnosis of MPE. It enables immediate intrapulmonary thrombolysis, which seems to be an effective therapeutic alternative in our group of patients with obstructive shock.

Gastric intramural PCO2 as monitor of perfusion failure during hemorrhagic and anaphylactic shock.

Indirect measurement of gastric intramural pH (pHG) utilizing a luminal tonometer in the stomach has been proposed for monitoring the severity and progression of perfusion failure. In the present study, we investigated gastric PCO2 and pHG as indicators and quantitators of the severity of perfusion failure in the experimental rodent model of both hemorrhagic and anaphylactic shock. Gastric intramural PCO2 (PGCO2) and pHG were directly measured with miniaturized sensors inserted into the anterior wall of the stomach. In hemorrhagic shock, animals were bled into a reservoir maintained at a pressure of 35 mmHg. pHG decreased from 7.39 +/- 0.08 to 6.67 +/- 0.11 (P < 0.01), and PGCO2 increased from 53 +/- 4 to 136 +/- 3 Torr (P < 0.01). Anaphylactic shock was induced in animals that had been sensitized 21 days before with crystallized ovalbumin. Antigen challenge produced an immediate reduction in mean aortic pressure from 144 to 60 mmHg. pHG decreased from 7.40 +/- 0.05 to 6.99 +/- 0.07 (P < 0.01), and PGCO2 increased from 48 +/- 5 to 133 +/- 9 Torr (P < 0.01). The increases in PGCO2 were highly correlated with decreases in gastric blood flow in both hemorrhagic (r = 0.96) and anaphylactic shock (r = 0.92). The correlations with pHG were more moderate. These experiments demonstrated prominent increases in PGCO2 and H+ during both hemorrhagic and anaphylactic shock. We further noted that the estimation of pHG based on the assumption that HCO3-concentrations of the stomach wall and arterial blood are the same was not fully sustained.

Mechanisms of myocardial hypercarbic acidosis during cardiac arrest.

During the global myocardial ischemia of cardiac arrest and during regional myocardial ischemia due to local impairment of coronary blood flow, intramyocardial carbon dioxide tensions (Pmco2) of ischemic myocardium increase to levels exceeding 400 Torr. The mechanism of such myocardial hypercarbic acidosis is as yet incompletely understood, specifically whether these increases in Pmco2 are due to increased oxidative metabolism, decreased CO2 removal, or buffering of metabolic acids. We therefore measured Pmco2 and the total CO2 content of rat hearts harvested before, during, and after resuscitation from cardiac arrest. Pmco2 significantly increased from an average of 63 to 209 Torr during a 4-min interval of untreated ventricular fibrillation. This was associated with concurrent decreases in intracellular pH from an average of 7.03 to 6.02 units. The total CO2 content of the myocardium simultaneously decreased from 17.0 to 16.5 mmol/kg. Accordingly, increases in Pmco2 and [H+] were observed in the absence of increases in the total CO2 content and therefore the calculated myocardial bicarbonate. These observations in the rat model implicate buffering of metabolic acids by bicarbonate rather than increases in CO2 production or decreases in CO2 removal as the predominant mechanism accounting for myocardial hypercarbia.

Treatment of out-of-hospital cardiac arrest in Ljubljana: outcome report according to the 'Utstein' style.

We investigated survival of patients with out-of-hospital cardiac arrest in Ljubljana according to the 'Utstein' style. Ljubljana consists of urban, suburban and semi-rural communities which encompass an area of 1615 km2 with 397306 residents. The area is served by a single response emergency medical system and local family practitioners. Between January 1, 1995 and December 31, 1997 cardiac arrest was confirmed in 966 patients. Cardiopulmonary resuscitation was attempted in 454 patients (47%). Collapse of presumed cardiac etiology (337 patients) was either bystander-witnessed (89%), un-witnessed (9%) or EMS personnel-witnessed (2%). Asystole was documented in 55%, ventricular fibrillation or tachycardia in 36% and other non-perfusing rhythms in 9% of these patients. Lay-bystander basic life support was performed in 19%. Nineteen patients (5.6%) survived to hospital discharge and 12 of them were independent in daily life. The survival of subgroups with bystanders-witnessed collapse and bystanders-witnessed ventricular fibrillation was 6.4 and 13%, respectively. Collapse of non-cardiac etiology (117 patients) was preceded by either respiratory failure (41), politrauma (22), circulatory shock (19), cerebrovascular incident (ten), intoxication (nine), strangulation (seven), electrocution (five) or drowning (four patients). Only five patients (4.2%) survived to hospital discharge. Hospital treatment of patients after successful initial cardiopulmonary resuscitation was associated with high mortality and required considerable resources.

Profound circulatory shock following heroin overdose.

A 17-year-old previously healthy girl with profound circulatory shock following a heroin overdose is reported. Except for opiates no other substances and specifically no cocaine were found in the blood and urine samples. Even though the mechanism of shock is not completely understood, severe depression of left ventricular contractility seems to be the predominant reason. Acute right heart failure with decreased pulmonary capillary wedge pressure and arterial vasodilatation resulting in maldistribution of cardiac output cannot be ruled out as possible contributing factors. The shock was successfully reversed with volume loading and a high dose of dobutamine. The recovery was uneventful and the patient was discharged with normal cardiac function.

[Optical coherence tomography of coronary arteries--a novel intravascular imaging modality]. / Optische Kohärenztomographie der Koronararterien.

Optical coherence tomography (OCT) is the latest intravascular imaging modality for the investigation of coronary arteries. It can be used in patients with stable coronary artery disease as well as in patients with acute coronary syndrome. Its almost microscope-like resolution of 10-20 µm (10-times greater than intravascular ultrasound) gives us the most detailed insight into the coronary artery wall in vivo so far.Optical coherence tomography can be used for accurate qualitative and quantitative assessment of stenoses in stable coronary artery disease and accurate guidance of percutaneous coronary interventions as well as accurate postprocedural control. In patients with acute coronary syndrome it can be used for the detection of culprit of the culprit lesion (vulnerable plaque) which allows the operator to cover not only angiographically tightest stenosis (angiographic culprit lesion, caused in most cases by thrombus only) but most importantly the vulnerable plaque, which led to the acute event, as well. Furthermore, optical coherence tomography allows accurate assessment of thrombotic burden, stent apposition/malapposition, edge dissections and tissue prolaps or thrombus protrusions throught stent struts, etc.

Early glycoprotein IIb-IIIa inhibitors in primary angioplasty-abciximab long-term results (EGYPT-ALT) cooperation: individual patient's data meta-analysis.

BACKGROUND: Even although time to treatment has been shown to be a determinant of mortality in primary angioplasty, the potential benefits are still unclear from early pharmacological reperfusion by glycoprotein (Gp) IIb-IIIa inhibitors. Therefore, the aim of this meta-analysis was to combine individual data from all randomized trials conducted on upstream as compared with late peri-procedural abciximab administration in primary angioplasty. METHODS: The literature was scanned using formal searches of electronic databases (MEDLINE and EMBASE) from January 1990 to December 2010. All randomized trials on upstream abciximab administration in primary angioplasty were examined. No language restrictions were enforced. RESULTS: We included a total of seven randomized trials enrolling 722 patients, who were randomized to early (n = 357, 49.4%) or late (n = 365, 50.6%) peri-procedural abciximab administration. No difference in baseline characteristics was observed between the two groups. Follow-up data were collected at a median (25th-75th percentiles) of 1095 days (720-1967). Early abciximab was associated with a significant reduction in mortality (primary endpoint) [20% vs. 24.6%; hazard ratio (HR) 95% confidence interval (CI) = 0.65 (0.42-0.98) P = 0.02, P(het) = 0.6]. Furthermore, early abciximab administration was associated with a significant improvement in pre-procedural thrombolysis in myocardial infarction (TIMI) 3 flow (21.6% vs. 10.1%, P < 0.0001), post-procedural TIMI 3 flow (90% vs. 84.8%, P = 0.04), an improvement in myocardial perfusion as evaluated by post-procedural myocardial blush grade (MBG) 3 (52.0% vs. 43.2%, P = 0.03) and ST-segment resolution (58.4% vs. 43.5%, P < 0.0001) and significantly less distal embolization (10.1% vs. 16.2%, P = 0.02). No difference was observed in terms of major bleeding complications between early and late abciximab administration (3.3% vs. 2.3%, P = 0.4). CONCLUSIONS: This meta-analysis shows that early upstream administration of abciximab in patients undergoing primary angioplasty for ST-segment elevation myocardial infarction (STEMI) is associated with significant benefits in terms of pre-procedural epicardial re-canalization and ST-segment resolution, which translates in to significant mortality benefits at long-term follow-up.

Early glycoprotein IIb-IIIa inhibitors in primary angioplasty (EGYPT) cooperation: an individual patient data meta-analysis.

BACKGROUND: Even though time-to-treatment has been shown to be a determinant of mortality in primary angioplasty, the potential benefits from early pharmacological reperfusion by glycoprotein (Gp) IIb-IIIa inhibitors are still unclear. The aim of this meta-analysis was to combine individual data from all randomised trials conducted on facilitated primary angioplasty by the use of early Gp IIb-IIIa inhibitors. METHODS AND RESULTS: The literature was scanned by formal searches of electronic databases (MEDLINE, EMBASE) from January 1990 to October 2007. All randomised trials on facilitation by the early administration of Gp IIb-IIIa inhibitors in ST-segment elevation myocardial infarction (STEMI) were examined. No language restrictions were enforced. Individual patient data were obtained from 11 out of 13 trials, including 1662 patients (840 patients (50.5%) randomly assigned to early and 822 patients (49.5%) to late Gp IIb-IIIa inhibitor administration). Preprocedural Thrombolysis in Myocardial Infarction Study (TIMI) grade 3 flow was more frequent with early Gp IIb-IIIa inhibitors. Postprocedural TIMI 3 flow and myocardial blush grade 3 were higher with early Gp IIb-IIIa inhibitors but did not reach statistical significance except for abciximab, whereas the rate of complete ST-segment resolution was significantly higher with early Gp IIb-IIIa inhibitors. Mortality was not significantly different between groups, although early abciximab demonstrated improved survival compared with late administration, even after adjustment for clinical and angiographic confounding factors. CONCLUSIONS: This meta-analysis shows that pharmacological facilitation with the early administration of Gp IIb-IIIa inhibitors in patients undergoing primary angioplasty for STEMI is associated with significant benefits in terms of preprocedural epicardial recanalisation and ST-segment resolution, which translated into non-significant mortality benefits except for abciximab.

Correlation between QTc interval duration and left ventricular systolic dysfunction in patients with acute myocardial infarction.

QTc interval and left ventricular regional wall motion abnormality score (WMS) were assessed in 61 consecutive patients with 4-day-old acute myocardial infarction (AMI). There were 45 men and 16 women, aged 60.6 +/- 8.7 years; 24 had anterior wall AMI and 37 had inferior wall AMI. Twenty-nine patients received thrombolytic treatment, which was presumably successful in 19. The longest QTc interval from a standard 12-lead electrocardiogram, corrected by Bazett's formula, was considered for the study. The WMS was evaluated echocardiographically. The authors found a statistically significant correlation between WMS and QTc interval duration; the correlation was stronger in patients with anterior AMI (r = .9, P < .001) than in those with inferior AMI (r = .66, P < .001). The WMS and QTc values were significantly lower in patients with successful thrombolytic treatment compared to those with unsuccessful thrombolysis (P < .003 and P < .002, respectively). The authors could demonstrate no significant correlation between serum potassium concentration and the QTc interval. In patients with anterior AMI, QTc interval duration might represent an additional marker of left ventricular systolic dysfunction. It could also be used as an additional noninvasive criterion of coronary artery reperfusion in patients with AMI.

Double vessel extension of spontaneous left main coronary artery dissection in young women treated with thrombolytics.

Spontaneous coronary artery dissection is an extremely rare cause of myocardial infarction. The prognosis and treatment of coronary artery dissection have not yet been defined. We report on a 42-year-old woman who was admitted to the emergency unit of a regional hospital with central chest pain and electrocardiographic signs of extensive acute anterior myocardial infarction (MI). She was treated with thrombolytics, yet her condition deteriorated rapidly, resulting in cardiogenic shock. An angiogram revealed dissection of the left main coronary artery that extended into the anterior descending (LAD) and circumflex arteries (LCX). At autopsy a recent anterolateral MI of the left ventricle was found. Dissection of the left coronary artery system was confirmed. Extension of the dissection may have been due to thrombolytic treatment.

Acute isoniazid neurotoxicity during preventive therapy.

OBJECTIVE: To describe rare side effects of treatment with isoniazid. DESIGN: Descriptive case report. SETTING: Medical intensive care unit in a university medical center. PATIENT: A 14-yr old previously healthy girl receiving preventive isoniazid therapy who suddenly developed generalized tonic-clonic seizures and coma. INTERVENTIONS: Patient was sedated and mechanically ventilated. She also received pyridoxine intravenously. MEASUREMENTS AND MAIN RESULTS: An isoniazid overdose was not confirmed. Computed tomography of the brain and electroencephalogram revealed nothing abnormal. Seizures gradually disappeared within 2 hrs after sedation and treatment with pyridoxine. The patient was discharged on day 14 without consequences and has been well for 10 mos. No seizures reappeared after isoniazid was discontinued. CONCLUSIONS: We caution against possible isoniazid neurotoxicity in healthy individuals using recommended preventive doses.

Spontaneous gasping increases the ability to resuscitate during experimental cardiopulmonary resuscitation.

OBJECTIVE: To evaluate the effect of spontaneous gasping on cardiorespiratory functions and the ability to resuscitate during experimental cardiac arrest. DATA SOURCES: Studies in rat and pig models during cardiac arrest and cardiopulmonary resuscitation (CPR). STUDY SELECTION: We retrospectively examined the role of spontaneous gasping during the course of experimental studies on cardiopulmonary resuscitation. DATA EXTRACTION: The data were extracted to illustrate the mechanisms of spontaneous gasping and its effects on pulmonary gas exchange and blood circulation during CPR. DATA SYNTHESIS: Spontaneous gasping increased PaO2 and decreased PaCO2 values during precordial compression in the absence of mechanical ventilation. The frequency of gasping during precordial compression was greater in successfully resuscitated animals. A significant linear correlation was established between coronary artery perfusion pressure and both the frequency (r2 = .90, p < .01) and the duration (r2 = 0.69, p < .01) of gasping during untreated ventricular fibrillation and before resuscitation was attempted. Like coronary perfusion pressure, the frequency and duration of gasping predicted the success of cardiac resuscitation attempts. CONCLUSIONS: Spontaneous gasping is associated with both pulmonary and hemodynamic effects during cardiac arrest in experimental animals. Spontaneous gasping is biologically useful and is predictive of a more favorable outcome of resuscitative efforts.

Ventricular fibrillation voltage as a monitor of the effectiveness of cardiopulmonary resuscitation.

Ventricular fibrillation (VF) voltage was previously identified as a predictor of the success of cardiopulmonary resuscitation. In the present study we investigated the mechanism by which VF voltage predicts the success of cardiac resuscitation in a well-established rodent model of cardiac arrest. After 4 minutes of untreated VF, precordial compression was initiated and maintained for 6 minutes. Increases in coronary perfusion pressure during precordial compression were associated with concomitant increases in VF voltage (r = 0.61, p = 0.013). Significantly greater coronary perfusion pressure (24 vs 17 mm Hg) and VF voltage (0.17 vs 0.12 mV) were observed in resuscitated animals. To obviate electrical artifacts produced by precordial compression, boluses of oxygenated blood were injected into the ascending aorta in another 5 animals as an alternative method of cardiac resuscitation. This restored myocardial perfusion before defibrillation. Increases in VF voltage from 0.04 mV to 0.47 mV during aortic infusions were again correlated with coronary perfusion pressure (r = 0.62, p < 0.01) and predicted the success of cardiac resuscitation. Greater VF voltages after initiation of cardiac resuscitation were associated with increases in myocardial creatine phosphate, from 0.23 to 0.70 mmol/kg wet weight, and significant decreases in lactate content, from 22.8 to 13.9 mmol/kg wet weight. Increases in creatine phosphate were highly correlated with increases in VF voltage (r = 0.99, p < 0.01). Accordingly, increases in VF voltage during cardiac resuscitation reflect increases in myocardial perfusion and favorable changes in myocardial energy metabolism. As such, VF voltage, like coronary perfusion pressure, serves as a quantitative predictor of the success of cardiopulmonary resuscitation.