Teri M. Kozik

Cardiovascular responses to energy drinks in a healthy population: The C-energy study

BACKGROUND Energy drink consumption has increased significantly over the past decade and is associated with greater than 20,000 emergency department visits per year. Most often these visits are due to cardiovascular complaints ranging from palpitations to cardiac arrest. OBJECTIVE To determine if energy drinks alter; blood pressure, electrolytes, activated bleeding time (ACT), and/or cardiac responses measured with a 12-lead electrocardiographic (ECG) Holter. METHODS Continuous ECG data was collected for five hours (30 minutes baseline and 4 hours post consumption [PC]). Subjects consumed 32 ounces of energy drink within one hour and data (vital signs and blood samples) was collected throughout the study period. Paired students t-test and a corresponding non-parametric test (Wilcoxon signed rank) were used for analysis of the data. RESULTS Fourteen healthy young subjects were recruited (mean age 28.6 years). Systolic blood pressure (baseline=132, ±7.83; PC=151, ±11.21; P=.001); QTc interval (baseline=423, ±22.74; PC=503, ±24.56; P<.001); magnesium level (baseline 2.04, ± 0.09; PC=2.13, ±0.15; P=.05); and calcium level (baseline=9.31, ±.28; PC=9.52, ±.22; P=.018) significantly increased from baseline. While potassium and ACT fluctuated (some subjects increased their levels while others decreased) these changes were not significant. Eight of the fourteen subjects (57%) developed a QTc >500 milliseconds PC. Other T-wave changes were noted in 9/14 (64.3%) subjects PC. CONCLUSIONS Energy drinks increased systolic blood pressure, altered electrolytes, and resulted in repolarization abnormalities. These physiological responses can lead to arrhythmias and other abnormal cardiac responses highlighting the importance that emergency room personnel assess for energy drink consumption and potential toxicity.

Clinical Utility of Ventricular Repolarization Dispersion for Real‐Time Detection of Non‐ST Elevation Myocardial Infarction in Emergency Departments

Background A specific electrocardiographic (ECG) marker of ischemia would greatly improve the speed and accuracy of detecting and treating non-ST elevation myocardial infarction (NSTEMI). We hypothesize that ischemia induces ventricular repolarization dispersion (VRD), altering the T-wave before any ST segment deviation. We sought to evaluate the clinical utility of VRD to (1) detect NSTEMI cases in the emergency department (ED) and (2) identify NSTEMI cases at high risk for in-hospital major adverse cardiac events (MACEs). Methods and Results We continuously recorded 12-lead Holter ECGs from chest pain patients upon their arrival to the ED. VRD was quantified using principal component analysis of the 12-lead ECG to compute a T-wave complexity ratio (ie, ratio of second to first eigenvectors of repolarization). Clinical outcomes were obtained from hospital records. The sample was composed mainly of older males (n=369; ages 63±12 years; 63% males), and 92 (25%) had NSTEMI and 26 (7%) had MACEs. Baseline T-wave complexity ratio modestly correlated with peak troponin levels (r=0.41; P<0.001) and was a good classifier of NSTEMI events (area under the curve=0.70). An increased T-wave complexity ratio on the presenting ECG was strongly associated with NSTEMI (odds ratio [OR]=3.8 [2.1 to 5.8]) and in-hospital MACE (OR=8.2 [3.1 to 21.5]). Conclusions A simple measure of global VRD on the presenting 12-lead ECG correlates with ischemic myocardial injury and can discriminate NSTEMI cases very early during evaluation. Prospective studies should validate these findings and test whether VRD can guide therapy.

A research method for detecting transient myocardial ischemia in patients with suspected acute coronary syndrome using continuous ST-segment analysis.

Each year, an estimated 785,000 Americans will have a new coronary attack, or acute coronary syndrome (ACS). The pathophysiology of ACS involves rupture of an atherosclerotic plaque; hence, treatment is aimed at plaque stabilization in order to prevent cellular death. However, there is considerable debate among clinicians, about which treatment pathway is best: early invasive using percutaneous coronary intervention (PCI/stent) when indicated or a conservative approach (i.e., medication only with PCI/stent if recurrent symptoms occur). There are three types of ACS: ST elevation myocardial infarction (STEMI), non-ST elevation MI (NSTEMI), and unstable angina (UA). Among the three types, NSTEMI/UA is nearly four times as common as STEMI. Treatment decisions for NSTEMI/UA are based largely on symptoms and resting or exercise electrocardiograms (ECG). However, because of the dynamic and unpredictable nature of the atherosclerotic plaque, these methods often under detect myocardial ischemia because symptoms are unreliable, and/or continuous ECG monitoring was not utilized. Continuous 12-lead ECG monitoring, which is both inexpensive and non-invasive, can identify transient episodes of myocardial ischemia, a precursor to MI, even when asymptomatic. However, continuous 12-lead ECG monitoring is not usual hospital practice; rather, only two leads are typically monitored. Information obtained with 12-lead ECG monitoring might provide useful information for deciding the best ACS treatment. Purpose. Therefore, using 12-lead ECG monitoring, the COMPARE Study (electroCardiographic evaluatiOn of ischeMia comParing invAsive to phaRmacological trEatment) was designed to assess the frequency and clinical consequences of transient myocardial ischemia, in patients with NSTEMI/UA treated with either early invasive PCI/stent or those managed conservatively (medications or PCI/stent following recurrent symptoms). The purpose of this manuscript is to describe the methodology used in the COMPARE Study. Method. Permission to proceed with this study was obtained from the Institutional Review Board of the hospital and the university. Research nurses identify hospitalized patients from the emergency department and telemetry unit with suspected ACS. Once consented, a 12-lead ECG Holter monitor is applied, and remains in place during the patients entire hospital stay. Patients are also maintained on the routine bedside ECG monitoring system per hospital protocol. Off-line ECG analysis is done using sophisticated software and careful human oversight.

Cardiac arrest from acquired long QT syndrome: A case report

BACKGROUND Many classes of medications initiated by clinicians can cause adverse events, such as cardiac disturbances. One such adverse outcome is that of acquired long QT syndrome, which can lead to arrhythmias and sudden death. When health care practitioners were surveyed about their knowledge of this condition, 20% indicated they knew very little about long QT syndromes and more than 30% failed to check on current therapy before prescribing QT-prolonging medications. METHODS A case will be presented to illustrate the importance of understanding this syndrome. RESULTS The causes and pathophysiology of acquired long QT syndrome are discussed, and the resources for clinicians to obtain more information and growing number of offending medications leading to acquired long QT syndrome are provided. CONCLUSIONS On-going education is needed to heighten awareness in the health care community to prevent the deleterious outcomes associated with medication induced acquired long QT syndrome.

Electrocardiographic evaluation of cardiovascular status.

The electrocardiogram (ECG) is indispensable for the diagnosis and management of patients with a wide variety of cardiac and noncardiac diseases. The purpose of this paper is focused on recent research that used ECG, specifically the long-QT interval and microvolt T wave alternans, for the evaluation of life-threatening ventricular arrhythmias. Although remaining to be validated, QT prolongation along with other emerging electrocardiographic indices such as T wave morphology, T peak-to-T end time, or beat-to-beat QT variability may be sensitive indicators of malignant polymorphic ventricular tachyarrhythmia, torsade de pointes. Microvolt T wave alternans may provide important information in identifying a low-risk group with left ventricular dysfunction who is unlikely to benefit from unnecessary prophylactic implantable cardioverter defibrillator therapy. These ECG markers have the potential to aid in the safe administration of individualized medications, avoidance of sudden cardiac death, and provision of a noninvasive strategy to identify patients who are most and least likely to benefit from expensive prophylactic implantable cardioverter defibrillator placement.

Holiday Heart Syndrome

Scenario: A 53-year-old male arrived at the mentally ill/chemically addicted unit with acute alcohol withdrawal. His electrocardiogram (ECG) showed the cardiac rhythm below. The patient was a recovering alcoholic but a week earlier had left his family and checked into a motel to drink alcohol. He had stopped eating and had been drinking continuously when he noticed chest palpitations and shortness of breath the day before Thanksgiving. However, he delayed going to the hospital until after Thanksgiving because he wanted to watch the football games. Before the diagnosis of alcoholism 2 years earlier, the business executive had no medical issues; in fact, he had been very healthy and had run marathons. A regular feature of the American Journal of Critical Care, the ECG Puzzler addresses electrocardiogram (ECG) interpretation for clinical practice. To send an eLetter or to contribute to an online discussion about this article, visit www.ajcconline.org and click “Respond to This Article” on either the full-text or PDF view of the article. We welcome letters regarding this feature.

Among Unstable Angina and Non-ST-Elevation Myocardial Infarction Patients, Transient Myocardial Ischemia and Early Invasive Treatment Are Predictors of Major In-hospital Complications.

Background:Treatment for unstable angina (UA) or non–ST-elevation myocardial infarction (NSTEMI) is aimed at plaque stabilization to prevent infarction. Two treatment strategies are (1) invasive (ie, cardiac catheterization laboratory <24 hours after admission) or (2) selectively invasive (ie, medications with cardiac catheterization laboratory >24 hours for recurrent symptoms). However, it is not known if the frequency of transient myocardial ischemia (TMI) or complications during hospitalization varies by treatment. Purpose:We aimed to (1) examine occurrence of TMI in UA/NSTEMI, (2) compare frequency of TMI by treatment pathway, and (3) determine predictors of in-hospital complications (ie, death, myocardial infarction [MI], pulmonary edema, shock, dysrhythmia with intervention). Methods:Hospitalized patients with coronary artery disease (ie, history of MI, percutaneous coronary intervention/stent, coronary artery bypass graft, >50% lesion via angiogram, or positive troponin) were recruited, and 12-lead electrocardiogram Holter initiated. Clinicians, blinded to Holter data, decided treatment strategy; offline analysis was done after discharge. Transient myocardial ischemia was defined as more than 1-mm ST segment ↑ or ↓, in more than 1 electrocardiographic lead, more than 1 minute. Results:Of 291 patients, 91% were white, 66% were male, 44% had prior MI, and 59% had prior percutaneous coronary intervention/stent or coronary artery bypass graft. Treatment pathway was early in 123 (42%) and selective in 168 (58%). Forty-nine (17%) had TMI: 19 (15%) early invasive, 30 (18%) selective (P = .637). Acute MI after admission was higher in patients with TMI regardless of treatment strategy (early: no TMI 4% vs yes TMI 21%; P = .020; selective: no TMI 1% vs yes TMI 13%; P = .0004). Predictors of major in-hospital complication were TMI (odds ratio, 9.9; 95% confidence interval, 3.84–25.78) and early invasive treatment (odds ratio 3.5; 95% confidence interval, 1.23–10.20). Conclusions:In UA/NSTEMI patients treated with contemporary therapies, TMI is not uncommon. The presence of TMI and early invasive treatment are predictors of major in-hospital complications.

Implantable Electrical Devices

Scenario: This electrocardiogram (ECG) was obtained in the emergency department from a 72-year-old male with chest pain and shortness of breath. The patient’s history included hypertension, coronary artery disease, hyperlipidemia, and urinary incontinence that was managed with a bladder stimulator. Given this ECG, the clinicians were concerned his cardiac pacemaker was misfiring, but the patient insisted he did not have a pacemaker. A regular feature of the American Journal of Critical Care, the ECG Puzzler addresses electrocardiogram (ECG) interpretation for clinical practice. To send an eLetter or to contribute to an online discussion about this article, visit www.ajcconline.org and click “Respond to This Article” on either the full-text or PDF view of the article. We welcome letters regarding this feature.

Unplanned transfer from the telemetry unit to the intensive care unit in hospitalized patients with suspected acute coronary syndrome.

BACKGROUND Most patients presenting with suspected acute coronary syndrome (ACS) are admitted to telemetry units. While telemetry is an appropriate level of care, acute complications requiring a higher level of care in the intensive care unit (ICU) occur. PURPOSE Among patients admitted to telemetry for suspected ACS, we determine the frequency of unplanned ICU transfer, and examine whether ECG changes indicative of myocardial ischemia, and/or symptoms preceded unplanned transfer. METHOD This was a secondary analysis from a study assessing occurrence rates for transient myocardial ischemia (TMI) using a 12-lead Holter. Clinicians were blinded to Holter data as it was used in the context research; off-line analysis was performed post discharge. Hospital telemetry monitoring was maintained as per hospital protocol. TMI was defined as >1mm ST-segment ↑ or ↓, in >1 ECG lead, >1minute. Symptoms were assessed by chart review. RESULTS In 409 patients (64±13years), most were men (60%), Caucasian (93%), and had a history of coronary artery disease (47%). Unplanned transfer to the ICU occurred in 9 (2.2%), was equivalent by gender, and age (no transfer 64±13years vs transfer 67±11years). Four patients were transferred following unsuccessful percutaneous coronary intervention (PCI) attempt, four due to recurrent angina, and one due to renal and hepatic failure. Mean time from admission to transfer was 13±6hours, mean time to ECG detected ischemia was 6±5hours, and 8.8±5hours for symptoms prompting transfer. In two patients ECG detected ischemia and acute symptoms prompting transfer were simultaneous. In five patients, ECG detected ischemia was clinically silent. All patients eventually had symptoms that prompted transfer to the ICU. In all nine patients, there was no documentation or nursing notes regarding bedside ECG monitor changes prior to unplanned transfer. Hospital length of stay was longer in the unplanned transfer group (2days ± 2 versus 6days ± 4; p=0.018). CONCLUSIONS In patients with suspected ACS, while unplanned transfer from telemetry to ICU is uncommon, it is associated with prolonged hospitalization. Two primary scenarios were identified; (1) following unsuccessful PCI, and (2) recurrent angina. Symptoms prompting unplanned transfer occurred, but happened on average 8.8 hours after hospital admission; whereas ECG detected ischemia preceding unplanned transfer occurred on average 6 hours after hospital admission.

Syncope With Profound Bradycardia

©2016 American Association of Critical-Care Nurses doi: http://dx.doi.org/10.4037/ajcc2016648 Salah S. Al-Zaiti is an assistant professor at the Department of Acute and Tertiary Care Nursing, University of Pittsburgh, Pennsylvania. Michele M. Pelter is an assistant professor at the the Department of Physiological Nursing at University of California, San Francisco, California. Teri M. Kozik is a nurse researcher at St. Joseph’s Medical Center, Stockton, California and Mary G. Carey is associate director for clinical nursing research, Strong Memorial Hospital, Rochester, New York . ECG Puzzler