Valproate-induced hyperammonemic encephalopathy: a case report and brief review of the literature.

Almost 50 years after its discovery, valproic acid remains a mainstay in the treatment of epilepsy, both alone and in combination with other anticonvulsants. It is also associated with a hyperammonemic encephalopathy, when used in combination with other drugs. We present a case of valproate-induced hyperammonemic encephalopathy in a patient on multiple anticonvulsant and psychotropic medications. The patient presented with altered mental status and became progressively more obtunded and finally began to experience seizures. Her symptoms resolved with the discontinuation of valproic acid and with supportive care.

Amiodarone-induced thrombosis: a case series and brief review of the literature.

Amiodarone is used extensively in clinical practice for the treatment of arrhythmias but is associated with a number of well-known side effects. We present 3 cases of extensive thrombosis occurring secondary to intravenous amiodarone. In cases like these, amiodarone must be stopped immediately and patients started on appropriate anticoagulation therapy. Providing education to nursing and pharmacy staff regarding the administration of IV amiodarone and the necessity of defining institutional guidelines are central to decreasing the risk of complications from using this widely available antiarrhythmic agent.

Impact of ischemia on left ventricular dyssynchrony by phase analysis of gated single photon emission computed tomography myocardial perfusion imaging.

BACKGROUND: There is increasing awareness of the value of phase analysis of gated tomographic myocardial perfusion imaging in assessing left ventricular (LV) dyssynchrony. A concern repeatedly raised in many studies is whether reversible defects in the stress images "ischemia" could affect the phase-derived standard deviation and bandwidth, the two commonly used dyssynchrony indices. We hypothesized that the stress and rest images should provide comparable information because the images are acquired 1 hour after the tracer injection. METHODS AND RESULTS: We studied two groups of patients with normal LV ejection fraction and no fixed perfusion defects. In group-1 (N = 20), the patients had reversible perfusion defects involving > 10% of the LV myocardium and in group-2 (N = 20), the patients had normal images. All patients underwent stress/rest-gated single photon emission computed tomography sestamibi imaging (the stress study was acquired with the lower dose) between January and March 2010. Patients with left bundle branch block or ventricular pacing were excluded. The patients in group-1 had a mean age of 61 ± 9 years, 65% were men, 75% Caucasians, and 70% had known prior coronary artery disease. The size of the reversible perfusion defect was 20 ± 13% (range 11%-50%) of the LV myocardium. The rest and stress phase-derived standard deviation (16 ± 6° vs 18 ± 8° and 16 ± 7° vs. 19 ± 6°) and the rest and stress bandwidth (42 ± 14° vs 46 ± 16° and 45 ± 17° vs 52 ± 12°), respectively, (P = NS for all) were similar in the two groups. The change (stress-rest) in standard deviation and bandwidth in groups 1 and 2 were not statistically significant (0.2 ± 3.1° vs 1.4 ± 4.7°, and 2 ± 13° vs 5 ± 13°, respectively, P = NS). There was no significant change from rest to stress in the standard deviation and the bandwidth in group-1 (P = .8 and .4, respectively) and group-2 (P = .2 and .08, respectively). There was no correlation between the size of the reversible perfusion defect and the change in phase standard deviation or bandwidth (r = 0.07 and 0.12, respectively, P = NS). CONCLUSIONS: The presence of even a large reversible perfusion defect does not alter the indices of mechanical dyssynchrony by phase analysis. Further, comparable information is obtained whether using a low dose or a high dose of the radiotracer.

Safety of regadenoson in patients with end-stage liver disease.

BACKGROUND: Regadenoson is a selective A(2A) receptor agonist that is used for vasodilator stress myocardial perfusion imaging (MPI). Since the drug is partially metabolized by the liver, its safety in patients with end-stage liver disease (ESLD) needs to be determined. METHODS AND RESULTS: We studied 168 consecutive patients with ESLD who had regadenoson stress gated single photon emission computed tomography MPI between January 2008 and March 2010 before planned orthotopic liver transplantation and compared the hemodynamic responses and safety profile to 168 control patients. There were 72 women (43%) in ESLD versus 87 (52%) in the control group (P = .1). The patients with ESLD were younger (58 ± 7 vs 62 ± 12 years, P = .0002), but more likely to be Caucasians (P = .002). The MPI images were normal in 161 patients (96%) in each group. The left ventricular ejection fraction was 72 ± 10% in ESLD and 66 ± 11% in the control patients (P = .0001). The heart rate increase in response to regadenoson was lower in patients with ESLD than in the control group (16 ± 11 vs 23 ± 16 bpm, P = .0001), but the changes in systolic and diastolic blood pressures were similar (-9 ± 12 vs -11 ± 14 mmHg and -6 ± 8 vs -7 ± 10 mmHg, respectively, P = NS). There were no deaths or medication-related adverse events that required hospitalization in either group within 30 days of the study. CONCLUSION: This is the first study to document the tolerability and safety profile of regadenoson in patients with ESLD.

Renal Artery Stenosis in a Young Female without Fibromuscular Dysplasia with Literature Review.

Renal artery stenosis (RAS) is rare in young patients without fibromuscular dysplasia (FMD). RAS is primarily classified as having two major etiologies, namely, atherosclerosis and FMD, with 90% and 10%, respectively. We report a case of a female in her mid 20s who developed hypertension due to RAS with no evidence of FMD or underlying renal dysfunction and underwent successful angioplasty and stenting.

ST-Elevation Myocardial Infarction after Pharmacologic Persantine Stress Test in a Patient with Wellens' Syndrome.

Wellens' syndrome, also known as LAD coronary T-wave inversion syndrome, is a characteristic ECG pattern that highly suggests critical stenosis of the proximal left anterior descending (LAD) coronary artery. 75% of patients with this finding go on to develop acute anterior wall myocardial infarction within one week unless prevented by early intervention on the culprit lesion. Most instances of ST-elevation occurring during cardiac stress testing have been observed with exercise, with only seven cases reported in the literature with pharmacologic stress. We present a case of a patient with no known cardiac disease who presented with chest pain and an ECG consistent with Wellens' syndrome that developed an acute anterior wall ST-elevation myocardial infarction after pharmacologic stress test.

Postpartum coronary vasospasm with literature review.

Acute myocardial infarction during pregnancy or the postpartum period is rare. We report a case of a 39-year-old postpartum woman who developed non-ST-elevation myocardial infarction due to severe diffuse coronary vasospasm. To our knowledge, this is the first case of angiographically evidenced coronary vasospasm, in a postpartum woman, with resistance to intracoronary nitroglycerin.

Applicability, limitations and downstream impact of echocardiography utilization based on the Appropriateness Use Criteria for transthoracic and transesophageal echocardiography.

To evaluate impact of echocardiography on patient management based on published transthoracic echocardiography (TTE) Appropriate Use Criteria (AUC). A prospective analysis of 170 consecutive outpatients who underwent TTE over a period of 2 months. Echo studies were classified into appropriate (A), inappropriate (I), or uncertain (U) based on the 2007/2011 AUC. A fourth group of studies which were not addressed by the 2007 AUC and therefore have unclassifiable category (UC) were also included in the analysis. The impact of AUC categorized echo results on patient management were evaluated by review of patient records in the ensuing 2 months. Based on 2007 AUC, 77% (131/170) were A, 9% were I, and 14% were UC category. Echo studies classified as A were more likely to be associated with new and major findings, (P = 0.034) and (P = 0.028) respectively when compared to all other studies. Furthermore, patient care intervention as defined in the study protocol was significantly associated with A studies as opposed to I and UC studies (P = 0.004). A studies were also more likely to have an impact on patient management when compared to other studies (P = 0.022). When studies were re-evaluated based on the 2011 AUC, all prior UC studies were now included in the U group in the new AUC of 2011, and there was no change in A or I study classification. This study demonstrates that the 2007/2011 AUC are helpful in evaluating practice patterns in a majority of outpatients undergoing TTE. Implementing AUC have a direct clinical impact as A studies are significantly more likely to reveal new and major findings, and more likely to result in a patient care intervention based on the echo findings.

Long-term effectiveness and safety of sirolimus drug-eluting stents.

The root cause of coronary artery disease is atherosclerosis, ie, intraluminal narrowing (stenosis) of the arteries that supply blood to tissues of the heart. The introduction of the drug-eluting stent over the past decade has revolutionized the field of interventional cardiology. It is used extensively in clinical practice for the treatment of coronary artery disease. The first drug-eluting stent to receive US Food and Drug Administration approval was the sirolimus-eluting stent. Recently, two other stent analogs of sirolimus were approved, ie, the zotarolimus-eluting stent and the everolimus-eluting stent. However, concern has arisen in recent years about the long-term safety and efficacy of drug-eluting stents, due to the occurrence of late adverse clinical events, such as stent thrombosis. This review focuses on clinical studies that have been performed with the sirolimus-eluting stent or its analogs. We discuss the pharmacology, safety, and various therapeutic options that exist when choosing stents for coronary artery disease. Our aim is to provide a thorough review of the long-term efficacy and safety of sirolimus drug-eluting stents, and also to discuss currently approved and promising investigational drug-eluting stents, in an effort to provide insight into how these stents are currently evolving and generate further investigation in this area.

Coronary anomaly and coronary artery fistula as cause of angina pectoris with literature review.

Coronary artery fistulas are rare anomalies of the coronary arteries that may sometimes cause symptoms by shunting blood flow away from the myocardial capillary network. We report the case of a 46-year old lady which shows the right coronary cusp giving rise to left main coronary artery called anomalous origin of a coronary artery (AOCA), and also a fistula between the left coronary artery and pulmonary artery. We describe our diagnostic approach and review the literature on the epidemiology, pathophysiology, the diagnostic modalities, and treatment options.

Prevalence, determinants, and clinical significance of cardiac troponin-I elevation in individuals admitted for a hypertensive emergency.

Hypertensive emergencies (HEs) are frequently accompanied with the release of cardiac troponin I (cTnI); however, determinants and clinical significance of cTnI elevation are largely unknown. A retrospective analysis was performed on patients (n = 567) with a diagnosis of HE admitted to two tertiary care centers that primarily serve an inner-city population. Data on demographics, clinical variables, and cTnI were collected through chart review. Using regression analyses, predictors of cTnI elevation were studied and the impact of cTnI on all-cause mortality (data obtained through the Social Security Death Index) was determined. cTnI elevation was observed in 186 (32.3%) admissions with a mean peak cTnI level of 4.06 ± 14.6 ng/mL. Predictors of cTnI were age, history of hypercholesterolemia, blood urea nitrogen level, pulmonary edema, and requirement for mechanical ventilation. During a mean follow-up period of 3.1 years, there were 211 deaths (37%). Neither the presence nor the extent of cTnI elevation was associated with mortality, while age, history of coronary artery disease, and blood urea nitrogen level were predictive of mortality. cTnI elevation commonly occurs in the setting of HEs. Despite a high incidence of adverse clinical outcomes, cTnI elevation was not an independent predictor of mortality in this population.

Left ventricular mechanical dyssynchrony by phase analysis of gated single photon emission computed tomography in end-stage renal disease.

The presence and degree of left ventricular (LV) dyssynchrony in patients with end-stage renal disease (ESRD) has not been well studied. We hypothesized that these patients would be more likely to have mechanical dyssynchrony than a control cohort. The indexes of LV mechanical dyssynchrony were measured by automated analysis of gated single photon emission computed tomography myocardial perfusion imaging in 290 patients with ESRD and 109 control patients. Only patients with normal myocardial perfusion imaging findings and a narrow QRS duration were included. The following variables were derived: LV ejection fraction (EF), volume, mass, and 2 indexes of dyssynchrony, the standard deviation and bandwidth. The standard deviation and bandwidth were significantly greater in those with ESRD (23° ± 13° vs 15° ± 6° and 65° ± 40° vs 42° ± 14°, respectively, p <0.001 for each). The LV volumes and LV mass were significantly lower and LVEF significantly greater in the control group than in the patients with ESRD (p <0.001 for each). The subgroup of 217 patients with ESRD and normal LVEF also had a significantly greater standard deviation and bandwidth than did the control group (21° ± 12° and 57° ± 35°, p <0.001 for each). However, their values were lower than those of the 73 patients with ESRD and a LVEF <50% (30° ± 13° and 90° ± 45°, p <0.001 for each). Finally, 25 patients (9%) with ESRD and none of the control group had a standard deviation >43° (p = 0.01). In conclusion, patients with ESRD had significantly more mechanical dyssynchrony than did the control group, even in absence of electrical dyssynchrony and abnormal LV perfusion or function.