Atrioventricular conduction abnormalities and atrioventricular blocks: ECG patterns and diagnosis

2018 ◽

pp. 1958-1961

Author(s):

S. Serge Barold

Keyword(s):

P Wave ◽

Conduction Time ◽

Type I ◽

Type Ii ◽

Av Block ◽

Ventricular Extrasystoles ◽

Av Conduction ◽

Pr Interval ◽

Before And After ◽

Second Degree

The diagnosis of first-degree and third-degree atrioventricular (AV) block is straightforward but that of second-degree AV block is more involved. Type I block and type II second-degree AV block are electrocardiographic patterns that refer to the behaviour of the PR intervals (in sinus rhythm) in sequences (with at least two consecutive conducted PR intervals) where a single P wave fails to conduct to the ventricles. Type I second-degree AV block describes visible, differing, and generally decremental AV conduction. Type II second-degree AV block describes what appears to be an all-or-none conduction without visible changes in the AV conduction time before and after the blocked impulse. The diagnosis of type II block requires a stable sinus rate, an important criterion because a vagal surge (generally benign) can cause simultaneous sinus slowing and AV nodal block, which can resemble type II block. The diagnosis of type II block cannot be established if the first post-block P wave is followed by a shortened PR interval or by an undiscernible P wave. A narrow QRS type I block is almost always AV nodal, whereas a type I block with bundle branch block barring acute myocardial infarction is infranodal in 60–70% of cases. All correctly defined type II blocks are infranodal. A 2:1 AV block cannot be classified in terms of type I or type II block, but it can be AV nodal or infranodal. Concealed His bundle or ventricular extrasystoles may mimic both type I or type II block (pseudo-AV block), or both

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Atrioventricular Conduction Delay in the Second Trimester Measured by Fetal Magnetocardiography

Journal of Immunology Research ◽

10.1155/2014/753953 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Annette Wacker-Gussmann ◽

Henrike Paulsen ◽

Krunoslav Stingl ◽

Johanna Braendle ◽

Rangmar Goelz ◽

...

Keyword(s):

Fetal Echocardiography ◽

Vascular Diseases ◽

P Wave ◽

Conduction Delay ◽

Study Group ◽

Conduction Time ◽

Av Block ◽

Collagen Vascular Diseases ◽

Fetal Magnetocardiography ◽

Av Conduction

Introduction. Fetal AV block in SSA/Ro pregnancies is generally not seen before 18-week gestation and onset is rare after 28-week gestation. If complete AV block appears, it is believed to be irreversible. The purpose of the study was to evaluate precise electrophysiological AV conduction from 18-week gestation onwards.Patients and Methods. 21 fetuses of pregnant women with collagen vascular diseases were included in the study group and 59 healthy fetuses served as controls. In addition to fetal echocardiography, fetal magnetocardiography (fMCG) was used to investigate precise electrophysiological fetal cardiac time intervals (fCTIs).Results. The PR segment (isoelectric segment between the end of the P wave and the start of the QRS complex) was significantly prolonged (P<0.0362nd trimester,P<0.0233rd trimester) in both trimesters within the study group. In fetuses less than 23-week gestational age, a nearly complete separation was found, where a PR segment of 60 ms or greater completely excluded control fetuses. All other fCTIs did not differ significantly. None of the fetuses progressed to a more advanced heart block.Conclusion. Slight antibody effects in pregnancy, leading to PR segment prolongation, can already be seen from 18-week gestation onwards by fMCG. Serial fetal Doppler echocardiography and additional fMCG can be useful methods to measure early and precise AV conduction time, to achieve best surveillance for these high-risk pregnancies.

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AV Block Second Degree Mobitz Type I by ECG Finding

10.32388/dfouyl ◽

2020 ◽

Author(s):

Keyword(s):

Type I ◽

Av Block ◽

Mobitz Type ◽

Second Degree

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Abstract 2023: Effect Of Chronic Stretch Reversal On Atrial Remodeling In Humans: Implications For The Atrial Fibrillation Substrate

Circulation ◽

10.1161/circ.116.suppl_16.ii_438 ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Bobby John ◽

Martin K Stiles ◽

Sunil T Chandy ◽

Pawel K Kuklik ◽

Glenn D Young ◽

...

Keyword(s):

Atrial Fibrillation ◽

Important Determinant ◽

P Wave ◽

Atrial Remodeling ◽

Conduction Time ◽

Atrial Arrhythmias ◽

Wave Duration ◽

P Wave Duration ◽

Before And After ◽

Mitral Commissurotomy

Background : Chronic atrial stretch is an important determinant for atrial fibrillation (AF). Whether relief of stretch reverses the substrate predisposed to AF is unknown. Methods: Twenty one pts (31±9 years) with mitral stenosis (MS; MVA 0.89±0.1cm 2 ) undergoing mitral commissurotomy (MC) were studied by electrophysiological or electroanatomical mapping of both atria before and after MC. Multipolar catheters were placed in the lateral RA, Crista (CT), coronary sinus (CS), septal RA and LA. We measured: effective refractory period (ERP) at the LA appendage, septal/lateral LA roof, posterior LA, inferior LA, proximal/distal CS, low/high LRA and SRA at 600 and 450ms; P wave duration (PWD); double potentials (DP) or fractionated signals (FS) along CT; and conduction time along CS, LRA, inferior LA and LA roof. Activation and voltage maps were created to evaluate changes in conduction and voltage. In 14 pts, RA studies were repeated ≥6 months after MC. Results : Following MC, there was significant increase in MVA (2.1±0.3 cm 2, p<0.0001) with decrease in LA (23±8 to 10±4 mmHg, p<0.0001) and PA pressures (38±17 to 27±14mmHg, p<0.0001) and LA volume (75±12 to 52±13ml, p<0.0001). This was associated with no change in ERP and No. of DP/FS along the CT but with reduction in PWD (139±19 to 135±20ms, p=0.047), increase in conduction velocity (CV) in LA (1.3±0.3 to 1.7±0.2m/s, p=0.005) and RA (1.0±0.1 to 1.3±0.3 m/s, p=0.007) and increase in LA voltage (1.7±0.6 to 2.5±1.0 mV, p=0.05). Late after MC, there was a further decrease in PWD and RA ERP, with increase in RA CV (1.0±0.1 to 1.3±0.2 m/s, p=0.01) and voltage (1.7±0.7 to 2.8±0.6 mV, p=0.004) but with no change in other parameters. See table for details of pts studied late after MC. Conclusion: The electrophysiologic and electroanatomic abnormalities within the atria that result from MS are reversed after MC. These observations suggest that the substrate predisposing to atrial arrhythmias may be reversed. Results

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Two Types of Interannual Variability of South China Sea Summer Monsoon Onset Related to the SST Anomalies before and after 1993/94

Journal of Climate ◽

10.1175/jcli-d-16-0065.1 ◽

2016 ◽

Vol 29 (19) ◽

pp. 6957-6971 ◽

Cited By ~ 17

Author(s):

Boqi Liu ◽

Congwen Zhu ◽

Yuan Yuan ◽

Kang Xu

Keyword(s):

Indian Ocean ◽

South China Sea ◽

Interannual Variability ◽

Summer Monsoon ◽

South China ◽

Type I ◽

Type Ii ◽

Enso Events ◽

Before And After ◽

Upper Level

Abstract An advance in the timing of the onset of the South China Sea (SCS) summer monsoon (SCSSM) during the period 1980–2014 can be detected after 1993/94. In the present study, the interannual variability of the SCSSM onset is classified into two types for the periods before and after 1993/94, based on their different characteristics of vertical coupling between the upper- and lower-tropospheric circulation and the differences in their related sea surface temperature anomalies (SSTAs). On the interannual time scale, type-I SCSSM onset is characterized by anomalous low-level circulation over the northern SCS during 1980–93, whereas type-II SCSSM onset is associated with anomalies of upper-level circulation in the tropics during 1994–2014. The upper-tropospheric thermodynamic field and circulation structures over the SCS are distinct between the two types of SCSSM onset, and this investigation shows the importance of the role played by the spring SSTAs in the southern Indian Ocean (SIO) and that of ENSO events in type-I and type-II SCSSM onset, respectively. In the early episode, the warming SIO SSTAs can induce an anomalous low-level anticyclone over the northern SCS that affects local monsoonal convection and rainfall over land to its north, demonstrating a high sensitivity of subtropical systems in type-I SCSSM onset. However, in type-II SCSSM onset during the later episode, the winter warm ENSO events and subsequent warming in the tropical Indian Ocean can influence the SCSSM onset by modulating the spring tropical temperature and upper-level pumping effect over the SCS.

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Energy metabolism in single human muscle fibers during contraction without and with epinephrine infusion

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1991.260.5.e713 ◽

1991 ◽

Vol 260 (5) ◽

pp. E713-E718 ◽

Cited By ~ 10

Author(s):

P. L. Greenhaff ◽

J. M. Ren ◽

K. Soderlund ◽

E. Hultman

Keyword(s):

Electrical Stimulation ◽

Muscle Fibers ◽

Type I ◽

Type Ii ◽

Short Term ◽

Epinephrine Infusion ◽

Before And After ◽

Type I Fibers ◽

Type Ii Fibers ◽

Femoris Muscle

The concentrations of glycogen, ATP, and phosphocreatine were analyzed in types I and II muscle fibers separated from biopsy samples of the quadriceps femoris muscle in five healthy volunteers. Muscle samples were obtained before and after 64 s of intermittent electrical stimulation. The experiment was carried out without and with epinephrine (Epi) infusion. Before stimulation the glycogen concentration was 11% higher in type II than in type I fibers (P less than 0.05). During electrical stimulation, rapid glycogenolysis occurred in type II fibers with hardly any detectable glycogenolysis in type I fibers. The calculated rates of glycogenolysis were 0.18 +/- 0.14 and 3.54 +/- 0.53 mmol glucose.kg dry muscle-1.s-1 in types I and II fibers, respectively. Epi infusion increased the rate of glycogenolysis during electrical stimulation in type I fibers (10-fold) but did not enhance the rate in type II fibers (P greater than 0.05). It is considered that, during short-term maximal muscle contraction, rapid muscle glycogenolysis occurs predominantly in type II fibers even though types I and II fibers are recruited and that, when Epi stimulation of glycogenolysis occurs, this is predominantly limited to type I fibers.

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Evaluation of hepatic CYP2D1 activity and hepatic clearance in type I and type II diabetic rat models, before and after treatment with insulin and metformin

DARU Journal of Pharmaceutical Sciences ◽

10.1007/s40199-020-00350-z ◽

2020 ◽

Vol 28 (2) ◽

pp. 479-487 ◽

Cited By ~ 1

Author(s):

Navid Neyshaburinezhad ◽

Maryam Seidabadi ◽

Mohammadreza Rouini ◽

Hoda Lavasani ◽

Alireza Foroumadi ◽

...

Keyword(s):

Hepatic Clearance ◽

Diabetic Rat ◽

Type I ◽

Type Ii ◽

Rat Models ◽

Before And After

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SPECIFIC ANTIBODY RESPONSE OF HUMAN SUBJECTS TO INTRACUTANEOUS INJECTION OF PNEUMOCOCCUS PRODUCTS

Journal of Experimental Medicine ◽

10.1084/jem.55.6.853 ◽

1932 ◽

Vol 55 (6) ◽

pp. 853-865 ◽

Cited By ~ 16

Author(s):

Maxwell Finland ◽

W. D. Sutliff

Keyword(s):

Human Subjects ◽

Type I ◽

Type Ii ◽

Specific Antibody Response ◽

Specific Antibodies ◽

Virulent Strains ◽

Before And After ◽

Specific Polysaccharide ◽

Protective Antibodies ◽

Intracutaneous Injection

The blood of 63 human subjects selected because of the absence of recent infections, was studied for its content of specific antibodies against virulent strains of Types I, II, and III pneumococci before and after intracutaneous injections of minute amounts of pneumococcus products. The simultaneous injection of the specific polysaccharides of all three types of pneumococci and of proteins and autolysates derived from Types I and II pneumococci was followed by the appearance or increase of pneumococcidal power in the whole defibrinated blood and, in most instances, by the appearance of mouse-protective antibodies and agglutinins for one or more types. A single intracutaneous injection of 0.01 mg. of the protein-free type-specific polysaccharide of either Type I, Type II, or Type III pneumococci or 4 similar daily injections was followed, in most of 29 subjects, by the appearance of antibodies against the homologous, but not against the heterologous type pneumococci. Some subjects showed a simultaneous lowering of a preexisting pneumococcidal power for heterologous or homologous types. A single intracutaneous injection of O.1 mg. of pneumococcus protein in 13 individuals was not followed by the appearance of specific antibodies to any appreciable degree. Single intracutaneous injections of small amounts of autolysates derived from virulent strains of Type I, II, or III pneumococci were followed in 11 subjects by a more or less general rise in the pneumococcidal power with the appearance of homologous type agglutinins and protective antibodies in about one-third of the subjects.

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