A single-center retrospective study on the incidence and clinical significance of the electrocardiographic "Triangular QRS-ST-T Waveform" pattern*.

BACKGROUND: The triangular QRS-ST-T waveform is a rare presentation of ST-segment elevation acute myocardial infarction associated with a poor in-hospital prognosis. OBJECTIVE: To evaluate the incidence and clinical implications of the QRS-ST-T waveform pattern. METHODS: Clinical data from non-pregnant adult patients who presented as STEMI activations at a single institution between 2017 and 2021 were reviewed. Patients who met electrocardiographic criteria for triangular QRS-ST-T waveform - a giant wave from the fusion of the QRS complex, the ST-segment, and the T-wave - were included in the study. RESULTS: There were 417 STEMI activations, eight (1.9%) of which fulfilled the criteria for the triangular QRS-ST-T waveform pattern on electrocardiography. Coronary angiography was performed in five of these patients, four of whom demonstrated a significant lesion to the left anterior descending artery. Three patients did not undergo angiography secondary to hemodynamic instability. Seven of the patients in our study experienced cardiogenic shock requiring vasopressor, inotropic, and/or mechanical support. Only two patients survived to discharge; one was successfully bridged to coronary artery bypass grafting via intra-aortic balloon pump, while the other underwent a staged percutaneous coronary intervention. CONCLUSIONS: The triangular QRS-ST-T waveform pattern is a rare ECG finding that may indicate hyper-acute STEMI and is an ominous sign of impending hemodynamic instability. Patients who survived received prompt aggressive therapeutic management.

The relationship between fasting blood glucose variability and coronary artery collateral formation in type 2 diabetes patients with coronary artery disease.

BACKGROUND: Coronary collaterals are an alternative source of blood supply to ischemic myocardium. Well-developed coronary collateral arteries in patients with coronary artery disease (CAD) limit the size of acute myocardial infarction and improves survival. The aim of this study was to investigate the relationship between glycemic variability and coronary collateral formation in patients with type 2 diabetes mellitus and CAD. METHODS: Consecutive patients undergoing percutaneous coronary intervention or coronary artery bypass grafting procedures were studied. Multivariate logistic regression models were used to examine the association between coronary artery collateral formation graded by Rentrope classification and glycemic variability, measured by coefficient variation of fasting blood glucose. RESULTS: In our study, we retrospectively enrolled 300 patients, of whom 239 were diabetic (age: 70.1±11.9, 56% men) and 61 were nondiabetic (age: 71.5±11.5, 72% men). Diabetic patients were further stratified as follows: those with poor coronary collateral artery development (n=171, age: 69.7±12.4, 55% men) and those with good coronary collateral artery development (n=68, age 71.1±10.8, 59% men) according to the Rentrope classification. Our findings did not show association between glycemic variability and coronary collateral vessels development after controlling for potential confounders (odds ratio: 2.51; 95% confidence interval: 0.57-11.03; P=0.22). The culprit lesion (≥75% stenosis) in the left anterior descending artery and the right coronary artery was more frequent in the good collateral group compared with the poor collateral group (66 vs. 50%, P=0.02; 63 vs. 45%, P=0.01 respectively). CONCLUSION: Glycemic variability is not associated with coronary collateral artery formation in patients with type 2 diabetes mellitus and CAD.

Gastric Varices in Absence of Splenic Vein Thrombosis: A Rare Entity of Idiopathic Non-Cirrhotic Portal Hypertension.

Idiopathic non-cirrhotic portal hypertension (INCPH) is portal hypertension (PHT) without cirrhosis and other identifiable causes. Esophageal and gastric varices are seen in INCPH which are mostly asymptomatic. We present a rare case of symptomatic isolated gastric varices (IGV) in the setting of INCPH. We report a case of a 60-year-old man who presented with an acute onset of hematemesis and no identifiable history. Upon further evaluation, he was found to have non-bleeding dilated gastric varices on esophagogastroduodenoscopy (EGD) and PHT without cirrhosis. Our patient is unique because he has symptomatic IGV and INCPH.

Pulmonary Alveolar Microlithiasis "Stone Lungs": A Case of Clinico-Radiological Dissociation.

Pulmonary alveolar microlithiasis (PAM) is a rare infiltrative lung disease characterized by deposition of spherical calcium phosphate microliths called calcospherites within the alveoli. PAM was first described by Friedrich in 1856 and then by Harbitz in 1918. The disease pathogenesis is based on mutations in the SLC34A2 gene that encodes for the Type IIb sodium-phosphate cotransporter. The majority of the patients are diagnosed at an early age, usually between the ages of 20 and 40 years. The hallmark of this disease is a striking dissociation between the radiological findings and the mild clinical symptoms.  We report a case of 35-year-old woman who presented post-motor vehicle accident with back pain and with minimal dyspnea on exertion. The final diagnosis was made after computed tomography and lung biopsy. The present case exhibits the remarkable clinico-radiological dissociation with complete calcification of the lungs on radiographic images with a relatively mild clinical presentation.

Whole-genome sequencing and phenotypic analysis of Bacillus subtilis mutants following evolution under conditions of relaxed selection for sporulation.

Little is known about how genetic variation at the nucleotide level contributes to competitive fitness within species. During a 6,000-generation study of Bacillus subtilis evolved under relaxed selection for sporulation, a new strain, designated WN716, emerged with significantly different colony and cell morphologies; loss of sporulation, competence, acetoin production, and motility; multiple auxotrophies; and increased competitive fitness (H. Maughan and W. L. Nicholson, Appl. Environ. Microbiol. 77:4105-4118, 2011). The genome of WN716 was analyzed by OpGen optical mapping, whole-genome 454 pyrosequencing, and the CLC Genomics Workbench. No large chromosomal rearrangements were found; however, 34 single-nucleotide polymorphisms (SNPs) and +1 frameshifts were identified in WN716 that resulted in amino acid changes in coding sequences of annotated genes, and 11 SNPs were located in intergenic regions. Several classes of genes were affected, including biosynthetic pathways, sporulation, competence, and DNA repair. In several cases, attempts were made to link observed phenotypes of WN716 with the discovered mutations, with various degrees of success. For example, a +1 frameshift was identified at codon 13 of sigW, the product of which (SigW) controls a regulon of genes involved in resistance to bacteriocins and membrane-damaging antibiotics. Consistent with this finding, WN716 exhibited sensitivity to fosfomycin and to a bacteriocin produced by B. subtilis subsp. spizizenii and exhibited downregulation of SigW-dependent genes on a transcriptional microarray, consistent with WN716 carrying a knockout of sigW. The results suggest that propagation of B. subtilis for less than 2,000 generations in a nutrient-rich environment where sporulation is suppressed led to rapid initiation of genomic erosion.

Characterization of soluble guanylate cyclase in NO-induced increases in aqueous humor outflow facility and in the trabecular meshwork.

PURPOSE: Nitric oxide (NO) increases the rate at which aqueous humor exits the eye; however, the involvement of soluble guanylate cyclase (sGC) is unknown. This study investigated the role of sGC in mediating the NO-induced increases in outflow facility. METHODS: Outflow facility was measured in porcine eyes using the anterior segment organ culture perfusion system. sGC activity was assessed by cGMP production in low-passage porcine and human trabecular meshwork (TM) cells and transformed human TM cells, as measured by enzyme immunoassay. sGCalpha and sGCbeta isoform expression were determined using Western blot analysis. RESULTS: Activation of sGC is necessary for the NO-induced increases in outflow facility (0.3215 microL/min per mm Hg [baseline outflow facility]+/-0.0837 [SEM]). NO resulted in increased sGC activity that was abolished by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-1 (ODQ). Western blot analysis of total protein demonstrated an equivalent ratio of sGCalpha and sGCbeta subunit expression. In transformed cell fractions, however, the level of cytoplasmic sGCalpha subunit expression was decreased compared with low-passage human TM cells. CONCLUSIONS: Activation of sGC is involved in the NO-induced increases in outflow facility. The expression of alpha and beta sGC subunits in an equivalent ratio would suggest a functional sGC heterodimer because DETA-NO increased cGMP levels in low-passage human and porcine TM cells. However, the inability of DETA-NO to cause increases in cGMP levels in transformed TM cells suggests that though the sGC heterodimer is necessary, it is not sufficient and may require other factors not present in transformed cells.