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Browsing by Author "Kovacs, Richard J."
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Item Athlete ECG T-wave abnormality interpretation patterns by non-experts(Elsevier, 2022-05) Torabi, Asad J.; Nahhas, Omar D.; Dunn, Reginald E.; Martinez, Matthew W.; Tucker, Andrew M.; Lincoln, Andrew E.; Kovacs, Richard J.; Emery, Michael S.; Medicine, School of MedicineBackground The presence of T-wave abnormalities (TWA) on an athlete's electrocardiogram (ECG) presents as a diagnostic challenge for physicians. Types of TWA patterns classified as abnormal by inexperienced readers have not been systematically analyzed. Methods ECGs from the 2011–2015 National Football League Scouting Combine (initially interpreted by general cardiologists) were retrospectively reviewed by expert sports cardiologists with strict application of the 2017 International Criteria. Patterns of TWA that were altered from the original interpretation were analyzed. Results The study included 1643 athletes (mean age 22 years). There was a 67 % reduction in the number of athletes with any TWA (p < 0.001) with 111 ECGs changed to normal. Inferior TWA was the most common interpreted initial ECG abnormality altered followed by anterior and lateral. Discussion This analysis revealed an initial high rate of TWA by non-expert readers. Tailored education programs to physicians who interpret athlete ECGs should highlight these specific T-wave patterns. We see this as an opportunity to make more clinicians aware of ECG interpretation guidelines as sports trained cardiologists are mostly self-taught.Item Athlete ECG T-wave abnormality interpretation patterns by non-experts(Elsevier, 2022-06-16) Torabi, Asad J.; Nahhas, Omar D.; Dunn, Reginald E.; Martinez, Matthew W.; Tucker, Andrew M.; Lincoln, Andrew E.; Kovacs, Richard J.; Emery, Michael S.; Graduate Medical Education, School of MedicineBackground: The presence of T-wave abnormalities (TWA) on an athlete's electrocardiogram (ECG) presents as a diagnostic challenge for physicians. Types of TWA patterns classified as abnormal by inexperienced readers have not been systematically analyzed. Methods: ECGs from the 2011-2015 National Football League Scouting Combine (initially interpreted by general cardiologists) were retrospectively reviewed by expert sports cardiologists with strict application of the 2017 International Criteria. Patterns of TWA that were altered from the original interpretation were analyzed. Results: The study included 1643 athletes (mean age 22 years). There was a 67 % reduction in the number of athletes with any TWA (p < 0.001) with 111 ECGs changed to normal. Inferior TWA was the most common interpreted initial ECG abnormality altered followed by anterior and lateral. Discussion: This analysis revealed an initial high rate of TWA by non-expert readers. Tailored education programs to physicians who interpret athlete ECGs should highlight these specific T-wave patterns. We see this as an opportunity to make more clinicians aware of ECG interpretation guidelines as sports trained cardiologists are mostly self-taught.Item Cardiac Safety of TGF-β Receptor I Kinase Inhibitor LY2157299 Monohydrate in Cancer Patients in a First-in-Human Dose Study(Springer US, 2015-10) Kovacs, Richard J.; Maldonado, Giuliana; Azaro, Analia; Fernández, Maria S.; Romero, Federico L.; Sepulveda-Sánchez, Juan M.; Corretti, Mary; Carducci, Michael; Dolan, Melda; Gueorguieva, Ivelina; Cleverly, Ann L.; Pillay, N. Sokalingum; Baselga, Jose; Lahn, Michael M.; Department of Medicine, IU School of MedicineTransforming growth factor-beta (TGF-β) signaling plays an important role in the fetal development of cardiovascular organs and in the repair mechanisms of the heart. Hence, inhibitors of the TGF-β signaling pathway require a careful identification of a safe therapeutic window and a comprehensive monitoring of the cardiovascular system. Seventy-nine cancer patients (67 glioma and 12 solid tumor) enrolled in a first-in-human dose study and received the TGF-β inhibitor LY2157299 monohydrate (LY2157299) as monotherapy (n = 53) or in combination with lomustine (n = 26). All patients were monitored using 2D echocardiography/color and Spectral Doppler (2D Echo with Doppler) every 2 months, monthly electrocardiograms, thorax computer tomography scans every 6 months, and monthly serum brain natriuretic peptide (BNP), troponin I, cystatin C, high-sensitivity C-reactive protein (hs-CRP). Administration of LY2157299 was not associated with medically relevant cardiovascular toxicities, including patients treated ≥6 months (n = 13). There were no increases of troponin I, BNP, or hs-CRP or reduction in cystatin C levels, which may have been considered as signs of cardiovascular injury. Blood pressure was generally stable during treatment. Imaging with echocardiography/Doppler showed an increase in mitral and tricuspid valve regurgitation by two grades of severity in only one patient with no concurrent clinical symptoms of cardiovascular injury. Overall, this comprehensive cardiovascular monitoring for the TGF-β inhibitor LY2157299 did not detect medically relevant cardiac toxicity and hence supports the evaluation of LY2157299 in future clinical trials.Item Effect of Transdermal Testosterone and Oral Progesterone on Drug-Induced QT Interval Lengthening in Older Men(American Heart Association, 2019-09-23) Muensterman, Elena Tomaselli; Jaynes, Heather A.; Sowinski, Kevin M.; Overholser, Brian R.; Shen, Changyu; Kovacs, Richard J.; Tisdale, James E.; Medicine, School of MedicineItem Effectiveness of a clinical decision support system for reducing the risk of QT interval prolongation in hospitalized patients(Ovid Technologies Wolters Kluwer - American Heart Association, 2014-05) Tisdale, James E.; Jaynes, Heather A.; Kingery, Joanna R.; Overholser, Brian R.; Mourad, Noha A.; Trujillo, Tate N.; Kovacs, Richard J.; Department of Medicine, IU School of MedicineBACKGROUND: We evaluated the effectiveness of a computer clinical decision support system (CDSS) for reducing the risk of QT interval prolongation in hospitalized patients. METHODS AND RESULTS: We evaluated 2400 patients admitted to cardiac care units at an urban academic medical center. A CDSS incorporating a validated risk score for QTc prolongation was developed and implemented using information extracted from patients' electronic medical records. When a drug associated with torsades de pointes was prescribed to a patient at moderate or high risk for QTc interval prolongation, a computer alert appeared on the screen to the pharmacist entering the order, who could then consult the prescriber on alternative therapies and implement more intensive monitoring. QTc interval prolongation was defined as QTc interval >500 ms or increase in QTc of ≥60 ms from baseline; for patients who presented with QTc >500 ms, QTc prolongation was defined solely as increase in QTc ≥60 ms from baseline. End points were assessed before (n=1200) and after (n=1200) implementation of the CDSS. CDSS implementation was independently associated with a reduced risk of QTc prolongation (adjusted odds ratio, 0.65; 95% confidence interval, 0.56-0.89; P<0.0001). Furthermore, CDSS implementation reduced the prescribing of noncardiac medications known to cause torsades de pointes, including fluoroquinolones and intravenous haloperidol (adjusted odds ratio, 0.79; 95% confidence interval, 0.63-0.91; P=0.03). CONCLUSIONS: A computer CDSS incorporating a validated risk score for QTc prolongation influences the prescribing of QT-prolonging drugs and reduces the risk of QTc interval prolongation in hospitalized patients with torsades de pointes risk factors.Item Enhanced Response to Drug-Induced QT Interval Lengthening in Patients with Heart Failure with Preserved Ejection Fraction(Elsevier, 2020-09) Tisdale, James E.; Jaynes, Heather A.; Overholser, Brian R.; Sowinski, Kevin M.; Fisch, Mark D.; Rodgers, Jo E.; Aldemerdash, Ahmed; Hsu, Chia-Chi; Wang, Nan; Tomaselli Muensterman, Elena; Rao, Vijay U.; Kovacs, Richard J.; Medicine, School of MedicineBackground: Patients with heart failure (HF) with reduced ejection fraction demonstrate enhanced response to drug-induced QT interval lengthening and are at increased risk for torsades de pointes. The influence of HF with preserved ejection fraction (HFpEF) on response to drug-induced QT lengthening is unknown. Methods and results: We administered intravenous ibutilide 0.003 mg/kg to 10 patients with HFpEF and 10 age- and sex-matched control subjects without HF. Serial 12-lead electrocardiograms were obtained for determination of QT intervals. Demographics, maximum serum ibutilide concentrations, area under the serum ibutilide concentration vs time curves, and baseline Fridericia-corrected QT (QTF) (417 ± 14 vs 413 ± 15 ms, P = .54) were similar in the HFpEF and control groups. Area under the effect (QTFvs time) curve (AUEC) from 0 to 1.17 hours during and following the ibutilide infusion was greater in the HFpEF group (519 ± 19 vs 497 ± 18 ms·h, P= .04), as was AUEC from 0 to 8.17 hours (3576 ± 125 vs 3428 ± 161 ms·h, P = .03) indicating greater QTF interval exposure. Maximum QTF (454 ± 15 vs 443 ± 22 ms, P = .18) and maximum percent increase in QTF from baseline (8.2 ± 2.1 vs 6.7 ± 1.9%, P = .10) in the 2 groups were not significantly different. Conclusions: HFpEF is associated with enhanced response to drug-induced QT interval lengthening.Item Influence of Oral Progesterone Administration on Drug-Induced QT Interval Lengthening: A Randomized, Double-Blind, Placebo-Controlled Crossover Study(Elsevier, 2016-12) Tisdale, James E.; Jaynes, Heather A.; Overholser, Brian R.; Sowinski, Kevin M.; Flockhart, David A.; Kovacs, Richard J.; Medicine, School of MedicineObjectives We tested the hypothesis that oral progesterone administration attenuates drug-induced QT interval lengthening. Background Evidence from preclinical and human investigations suggests that higher serum progesterone concentrations may be protective against drug-induced QT interval lengthening. Methods In this prospective, double-blind, crossover study, 19 healthy female volunteers (21-40 years) were randomized to receive progesterone 400 mg or matching placebo orally once daily for 7 days timed to the menses phase of the menstrual cycle (between-phase washout period = 49 days). On day 7, ibutilide 0.003 mg/kg was infused over 10 minutes, after which QT intervals were recorded and blood samples collected for 12 hours. Prior to the treatment phases, subjects underwent ECG monitoring for 12 hours to calculate individualized heart rate-corrected QT intervals (QTcI). Results Fifteen subjects completed all study phases. Maximum serum ibutilide concentrations in the progesterone and placebo phases were similar (1247±770 vs 1172±709 pg/mL, p=0.43). Serum progesterone concentrations were higher during the progesterone phase (16.2±11.0 vs 1.2±1.0 ng/mL, p<0.0001), while serum estradiol concentrations in the two phases were similar (89.3±62.8 vs 71.8±31.7 pg/mL, p=0.36). Pre-ibutilide lead II QTcI was significantly lower in the progesterone phase (412±15 vs 419±14 ms, p=0.04). Maximum ibutilide-associated QTcI (443±17 vs 458±19 ms, p=0.003), maximum percent increase in QTcI from pretreatment value (7.5±2.4 vs 9.3±3.4%, p=0.02) and area under the effect (QTcI) curve during the first hour post-ibutilide (497±13 vs 510±16 ms-hr, p=0.002) were lower during the progesterone phase. Progesterone-associated adverse effects included fatigue/malaise and vertigo. Conclusions Oral progesterone administration attenuates drug-induced QTcI lengthening.Item Influence of Zoledronic Acid on Atrial Electrophysiological Parameters and Electrocardiographic Measurements(Wiley Blackwell (John Wiley & Sons), 2015-06) Tisdale, James E.; Allen, Matthew R.; Overholser, Brian R.; Jaynes, Heather A.; Kovacs, Richard J.; Department of Anatomy & Cell Biology, IU School of MedicineINTRODUCTION: Our objective was to determine effects of zoledronic acid (ZA) on atrial electrophysiological parameters and electrocardiographic measurements. METHODS AND RESULTS: Ex vivo perfusion study: Isolated guinea pig hearts were perfused with modified Krebs-Henseleit (K-H) buffer with or without ZA 0.07 mg/kg/L (each n = 6). In ZA-perfused hearts, atrial action potential at 90% repolarization (APD90 ) decreased more from baseline than in controls (-23.2% ± -5.1% vs. -2.1% ± -8.1%, P < 0 .0001), as did APD30 (-28.8% ± -3.8% vs. -2.1% ± -2.1%, P < 0.0001). In vivo dose-response study: Guinea pigs underwent intraperitoneal injections every 2 weeks in 1 of 4 groups (each n = 8): ZA 0.007 mg/kg (low-dose), ZA 0.07 mg/kg (medium-dose), ZA 0.7 mg/kg (high-dose), or placebo. Hearts were excised at 8 weeks and perfused with modified K-H. Atrial effective refractory period (ERP) was lower with medium- and high-dose ZA versus placebo (P = 0.004). Atrial APD30 was lower with high-dose ZA versus placebo, low and medium doses (P < 0.001). Canine ECG study: Mature female beagles received intravenous ZA 0.067 mg/kg or saline (placebo; each n = 6) every 2 weeks for 12 weeks. P wave dispersion was greater in the ZA group (7.7 ± 3.7 vs. 3.4 ± 2.6 ms, P = 0.04). There were no significant differences in P wave index, maximum or minimum P wave duration, or PR interval. CONCLUSION: ZA shortens left atrial APD and ERP and increases P wave dispersion.Item Ondansetron blocks wild-type and p.F503L variant small-conductance Ca2+-activated K+ channels(American Physiological Society, 2018-08-01) Ko, Jum-Suk; Guo, Shuai; Hassel, Jonathan; Celestino-Soper, Patricia; Lynnes, Ty C.; Tisdale, James E.; Zheng, James J.; Taylor, Stanley E.; Foroud, Tatiana; Murray, Michael D.; Kovacs, Richard J.; Li, Xiaochun; Lin, Shien-Fong; Chen, Zhenhui; Vatta, Matteo; Chen, Peng-Sheng; Rubart, Michael; Medicine, School of MedicineApamin-sensitive small-conductance Ca2+-activated K+ (SK) current ( IKAS) is encoded by Ca2+-activated K+ channel subfamily N ( KCNN) genes. IKAS importantly contributes to cardiac repolarization in conditions associated with reduced repolarization reserve. To test the hypothesis that IKAS inhibition contributes to drug-induced long QT syndrome (diLQTS), we screened for KCNN variants among patients with diLQTS, determined the properties of heterologously expressed wild-type (WT) and variant KCNN channels, and determined if the 5-HT3 receptor antagonist ondansetron blocks IKAS. We searched 2,306,335 records in the Indiana Network for Patient Care and found 11 patients with diLQTS who had DNA available in the Indiana Biobank. DNA sequencing discovered a heterozygous KCNN2 variant (p.F503L) in a 52-yr-old woman presenting with corrected QT interval prolongation at baseline (473 ms) and further corrected QT interval lengthening (601 ms) after oral administration of ondansetron. That patient was also heterozygous for the p.S38G and p.P2835S variants of the QT-controlling genes KCNE1 and ankyrin 2, respectively. Patch-clamp experiments revealed that the p.F503L KCNN2 variant heterologously expressed in human embryonic kidney (HEK)-293 cells augmented Ca2+ sensitivity, increasing IKAS density. The fraction of total F503L-KCNN2 protein retained in the membrane was higher than that of WT KCNN2 protein. Ondansetron at nanomolar concentrations inhibited WT and p.F503L SK2 channels expressed in HEK-293 cells as well as native SK channels in ventricular cardiomyocytes. Ondansetron-induced IKAS inhibition was also demonstrated in Langendorff-perfused murine hearts. In conclusion, the heterozygous p.F503L KCNN2 variant increases Ca2+ sensitivity and IKAS density in transfected HEK-293 cells. Ondansetron at therapeutic (i.e., nanomolar) concentrations is a potent IKAS blocker. NEW & NOTEWORTHY We showed that ondansetron, a 5-HT3 receptor antagonist, blocks small-conductance Ca2+-activated K+ (SK) current. Ondansetron may be useful in controlling arrhythmias in which increased SK current is a likely contributor. However, its SK-blocking effects may also facilitate the development of drug-induced long QT syndrome.Item Phosphorylation of the RSRSP stretch is critical for splicing regulation by RNA-Binding Motif Protein 20 (RBM20) through nuclear localization(Nature Publishing Group, 2018-06-12) Murayama, Rie; Kimura-Asami, Mariko; Togo-Ohno, Marina; Yamasaki-Kato, Yumiko; Naruse, Taeko K.; Yamamoto, Takeshi; Hayashi, Takeharu; Ai, Tomohiko; Spoonamore, Katherine G.; Kovacs, Richard J.; Vatta, Matteo; Iizuka, Mai; Saito, Masumi; Wani, Shotaro; Hiraoka, Yuichi; Kimura, Akinori; Kuroyanagi, Hidehito; Medicine, School of MedicineRBM20 is a major regulator of heart-specific alternative pre-mRNA splicing of TTN encoding a giant sarcomeric protein titin. Mutation in RBM20 is linked to autosomal-dominant familial dilated cardiomyopathy (DCM), yet most of the RBM20 missense mutations in familial and sporadic cases were mapped to an RSRSP stretch in an arginine/serine-rich region of which function remains unknown. In the present study, we identified an R634W missense mutation within the stretch and a G1031X nonsense mutation in cohorts of DCM patients. We demonstrate that the two serine residues in the RSRSP stretch are constitutively phosphorylated and mutations in the stretch disturb nuclear localization of RBM20. Rbm20 S637A knock-in mouse mimicking an S635A mutation reported in a familial case showed a remarkable effect on titin isoform expression like in a patient carrying the mutation. These results revealed the function of the RSRSP stretch as a critical part of a nuclear localization signal and offer the Rbm20 S637A mouse as a good model for in vivo study.