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Charles D Swerdlow - One of the best experts on this subject based on the ideXlab platform.
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sinus Rhythm R Wave amplitude as a pRedictoR of ventRiculaR fibRillation undeRsensing in patients with implantable caRdioveRteR defibRillatoR
Heart Rhythm, 2015Co-Authors: Linda L Ruetz, Jodi Koehler, Mark L Brown, Troy E Jackson, Paul A Belk, Charles D SwerdlowAbstract:BackgRound VentRiculaR fibRillation (VF) is induced duRing implantable caRdioveRteR-defibRillatoR (ICD) implantation to ensuRe that the ICD will sense, detect, and defibRillate VF. ICD implant guidelines state that the amplitude of the sinus Rhythm R Wave RecoRded fRom the ventRiculaR electRogRam should have amplitude ≥5 mV. No study has tested the Relationship between sinus Rhythm R-Wave amplitude and VF sensing using modeRn, tRansvenous sensing electRodes. Objective The goal of this study was to deteRmine whetheR theRe is a sinus Rhythm R-Wave amplitude cutoff that can be used to deteRmine which patients aRe not at Risk of VF undeRsensing. Methods A RetRospective analysis of induced and spontaneous VF episodes fRom 2 clinical tRials with 2022 patients was peRfoRmed. Episodes with undeRsensing duRing the initial detection of VF weRe identified, and the distRibution of sinus Rhythm R-Wave amplitudes foR patients with and without VF undeRsensing was analyzed. Results Only 3% of analyzed induced VF episodes weRe consideRed to have VF undeRsensing, and none had clinically significant detection delays. TheRe was no coRRelation between device-measuRed, Rectified sinus Rhythm R-Wave amplitude and VF undeRsensing at the time of implantation oR duRing follow-up, although Conclusion We analyzed tRue bipolaR sensing of induced VF oR spontaneous ventRiculaR tachycaRdia/VF detected in the ICD VF zone. Sensing of VF was so Reliable that clinically significant undeRsensing did not occuR. OuR findings do not suppoRt any Recommended minimum sinus Rhythm R Wave to ensuRe Reliable sensing of VF oR the necessity of inducing VF to veRify sensing foR Rectified sinus Rhythm R-Waves with amplitude ≥3 mV.
Antonio L'abbate - One of the best experts on this subject based on the ideXlab platform.
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A PRominent R Wave in V1 but not in V2 Is a Specific Sign of a LaRge LateRal TRansmuRal InfaRction
Revista espanola de cardiologia (English ed.), 2012Co-Authors: Daniele Rovai, Gianluca Di Bella, Giuseppe Rossi, Alessandro Pingitore, Antonio L'abbateAbstract:INTRODUCTION AND OBJECTIVES In the absence of Right ventRiculaR hypeRtRophy oR bundle-bRanch block, a pRominent R Wave in V(1) oR V(2) is consideRed to Reflect a lateRal myocaRdial infaRction. We investigated the diffeRences in infaRct location, size and tRansmuRal extent between patients with pRominent R Wave in V(1) and those with pRominent R Wave in V(2). METHODS We studied 50 patients with a pRevious fiRst infaRction involving left ventRiculaR infeRioR and/oR lateRal wall at contRast-enhanced magnetic Resonance. RESULTS A pRominent R Wave in V(1) was pResent in 8 patients (16%), in V(2) in 23 (46%). At magnetic Resonance, the infaRction involved the infeRioR wall in 11 patients (22%), the lateRal wall in 6 (12%), and both walls in 33 patients (66%). The sensitivity of a pRominent R Wave in V(1) in detecting a lateRal infaRction was low (17.9%), while the specificity was high (90.9%). The sensitivity and specificity of a pRominent R Wave in V(2) weRe 46.2% and 54.5%, Respectively. In patients with a pRominent R Wave in V(1), infaRct size and lateRal and tRansmuRal extent weRe gReateR than in patients without this patteRn (P
Javier Garcianiebla - One of the best experts on this subject based on the ideXlab platform.
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new electRocaRdiogRaphic cRiteRia to diffeRentiate the type 2 bRugada patteRn fRom electRocaRdiogRam of healthy athletes with R Wave in leads v1 v2
Europace, 2014Co-Authors: Guillem Serra, Adrian Baranchuk, Antoni Bayesdeluna, Josep Brugada, Diego Goldwasser, Lucio Capulzini, David Arazo, Araceli Boraita, Mariaeugenia Heras, Javier GarcianieblaAbstract:Aims Diagnosis of Type-2 BRugada patteRn Remains challenging and it could be confused with otheR electRocaRdiogRam (ECG) patteRns pResenting an R ′-Wave in leads V1–V2 like in healthy athletes. This could impact theiR ability to peRfoRm competitive spoRts. The aim of the study was to evaluate, as a pRoof of concept, the new ECG cRiteRia to diffeRentiate the Type-2 BRugada patteRn fRom the ECG patteRn of healthy athletes depicting an R ′-Wave in leads V1–V2. Methods and Results SuRface ECGs fRom 50 patients with BRugada syndRome and type-2 BRugada patteRn and 58 healthy athletes with an R ′-Wave in leads V1–V2 weRe analysed. DiffeRent cRiteRia based on the chaRacteRistics of the tRiangle foRmed by the ascendant and descendant aRms of the R ′-Wave in leads V1–V2 weRe compaRed. The duRation of the base of the tRiangle at 0.5 mV (5 mm) fRom high take-off ≥160 ms (4 mm) has a specificity (SP) of 95.6%, sensitivity (SE) 85%, positive pRedictive value (PPV) 94.4%, and negative pRedictive value (NPV) 87.9%. The duRation of the base of the tRiangle at the isoelectRic line ≥60 ms (1.5 mm) in leads V1–V2 has an SP of 78%, SE 94.8%, PPV 79.3%, and NPV 93.5%. The Ratio of the base at isoelectRic line/height fRom the baseline to peak of R ′-Wave in leads V1–V2 has an SP of 92.1%, SE 82%, PPV 90.1%, and NPV 83.3%. Conclusions The thRee new ECG cRiteRia weRe accuRate to distinguish the Type-2 BRugada patteRn fRom the ECG patteRn with an R ′-Wave in healthy athletes. The duRation of the base of the tRiangle at 0.5 mV fRom the high take-off is the easiest to measuRe and may be used in clinical pRactice.
John B Holcomb - One of the best experts on this subject based on the ideXlab platform.
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R Wave amplitude in lead ii of an electRocaRdiogRaph coRRelates with centRal hypovolemia in human beings
Academic Emergency Medicine, 2006Co-Authors: John G Mcmanus, Victor A Convertino, William H. Cooke, David A Ludwig, John B HolcombAbstract:AbstRact : Objectives: PRevious animal and human expeRiments have suggested that Reduction in centRal blood volume eitheR incReases oR decReases the amplitude of R Waves in vaRious electRocaRdiogRaph (ECG) leads depending on undeRlying pathophysiology. In this investigation, we used gRaded centRal hypovolemia in adult volunteeR subjects to test the hypothesis that modeRate Reductions in centRal blood volume incReases R-Wave amplitude in lead II of an ECG. Methods: A fouR-lead ECG tRacing, heaRt Rate (HR), estimated stRoke volume (SV), systolic blood pRessuRe, diastolic blood pRessuRe, and mean aRteRial pRessuRe weRe measuRed duRing baseline supine Rest and duRing pRogRessive Reductions of centRal blood volume to an estimated volume loss of gReateR than 1,000 mL with application of loweR-body negative pRessuRe (LBNP) in 13 healthy human volunteeR subjects. Results: LoweR-body negative pRessuRe Resulted in a significant pRogRessive Reduction in centRal blood volume, as indicated by a maximal decRease of 65% in SV and maximal elevation of 56% in HR fRom baseline to 60 mm Hg LBNP. R-Wave amplitude incReased (p less than 0.0001) lineaRly with pRogRessive LBNP. The amalgamated coRRelation (R2) between aveRage stRoke volume and aveRage R-Wave amplitude at each LBNP stage was -0.989. Conclusions: These Results suppoRt ouR hypothesis that Reduction of centRal blood volume in human beings is associated with incReased R-Wave amplification in lead II of an ECG.
Natasja M S De Groot - One of the best experts on this subject based on the ideXlab platform.
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usefulness of the R Wave sign as a pRedictoR foR ventRiculaR tachyaRRhythmia in patients with bRugada syndRome
American Journal of Cardiology, 2017Co-Authors: Ahmed A Y Ragab, Charlotte A Houck, Lisette J M E Van Der Does, Eva A H Lanters, Danielle E Burghouwt, Agnes J Q M Muskens, Natasja M S De GrootAbstract:BRugada syndRome (BRS) is an autosomal dominant channelopathy which is Responsible foR a laRge numbeR of sudden caRdiac deaths in young subjects without stRuctuRal abnoRmalities. The most challenging step in management of patients with BRS is identifying who is at Risk foR developing malignant ventRiculaR tachyaRRhythmia (VTA). In patients with BRS, conduction delay in the Right ventRiculaR outflow tRact (RVOT) causes a pRominent R Wave in lead aVR. This electRocaRdiogRaphic paRameteR can be useful to detect these high-Risk patients. The goal of this study was to test the significance of R-Wave elevation in lead aVR as a pRedictoR foR VTA in patients with BRS. In this RetRospective study, we included 132 patients with BRS (47 ± 15 yeaRs, 65% men) who visited the outpatient clinic foR caRdiogenetic scReening. Patients' medical RecoRds weRe examined foR the pResence of a positive R-Wave sign in lead aVR and VTA. A positive R-Wave sign in lead aVR was obseRved in 41 patients (31%). This sign was moRe fRequently obseRved in patients who expeRienced VTA (n = 24) befoRe the initial diagnosis, duRing electRophysiological studies, oR duRing follow-up (p <0.001). The positive R-Wave sign occuRRed moRe fRequently in symptomatic patients with a histoRy of an out of hospital caRdiac aRRest, VTA, oR syncope than asymptomatic patients (60% vs 26%; p = 0.002). DuRing the follow-up peRiod, this sign was moRe fRequently detected in patients who developed eitheR de novo (50%) oR RecuRRent VTA (80%) (p = 0.017). MultivaRiable RegRession analysis showed that R-Wave sign is an independent pRedictoR foR VTA development (odds Ratio 4.8, 95% confidence inteRval 1.79 to 13.27). The pResence of a positive R-Wave sign in lead aVR is associated with the development of VTA. In conclusion, positive R-Wave sign in lead aVR can be used to identify patients with BRS at Risk foR malignant VTA.
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Usefulness of the R-Wave Sign as a PRedictoR foR VentRiculaR TachyaRRhythmia in Patients With BRugada SyndRome.
The American journal of cardiology, 2017Co-Authors: Ahmed A Y Ragab, Charlotte A Houck, Lisette J M E Van Der Does, Eva A H Lanters, Danielle E Burghouwt, Agnes J Q M Muskens, Natasja M S De GrootAbstract:BRugada syndRome (BRS) is an autosomal dominant channelopathy which is Responsible foR a laRge numbeR of sudden caRdiac deaths in young subjects without stRuctuRal abnoRmalities. The most challenging step in management of patients with BRS is identifying who is at Risk foR developing malignant ventRiculaR tachyaRRhythmia (VTA). In patients with BRS, conduction delay in the Right ventRiculaR outflow tRact (RVOT) causes a pRominent R Wave in lead aVR. This electRocaRdiogRaphic paRameteR can be useful to detect these high-Risk patients. The goal of this study was to test the significance of R-Wave elevation in lead aVR as a pRedictoR foR VTA in patients with BRS. In this RetRospective study, we included 132 patients with BRS (47 ± 15 yeaRs, 65% men) who visited the outpatient clinic foR caRdiogenetic scReening. Patients' medical RecoRds weRe examined foR the pResence of a positive R-Wave sign in lead aVR and VTA. A positive R-Wave sign in lead aVR was obseRved in 41 patients (31%). This sign was moRe fRequently obseRved in patients who expeRienced VTA (n = 24) befoRe the initial diagnosis, duRing electRophysiological studies, oR duRing follow-up (p
