Two P waves followed by one QRS complex: What is the mechanism?

Background: This study aimed to show the impairment of autonomic cardiac conduction causing bradycardia and/or electrocardiographic alterations in children affected by spinal muscular atrophy type 1 and 2 (SMA 1 and 2). Methods: We included 25 spinal muscular atrophy patients, admitted from November 2016 to May 2017. All patients underwent an electrocardiographic examination and we studied PR and QRS intervals, P-waves and QRS amplitudes, and heart rate in spinal muscular atrophy patients compared to a control group. Results: In all patients, we found longer PRi and QRSi ( P < .05), lower P-wave and QRS complex amplitudes ( P < .01), and a decreased heart rate ( P < .01) with respect to controls. When we divided our patients into SMA1 and SMA2 subgroups, we found that statistical differences were maintained for P-wave and QRS complex amplitudes and heart rate, but not for PRi and QRSi with respect to controls. Conclusion: We suggest the hypothesis of SMN expression on cardiac tissue condition and/or autonomic cardiac conduction.

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Multifocal atrial tachycardia

10.1093/med/9780199568741.003.0113 ◽

2018 ◽

Author(s):

Michael Jones ◽

Norman Qureshi ◽

Kim Rajappan

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Atrial Tachycardia ◽

The Other ◽

P Wave ◽

Qrs Complex ◽

P Waves ◽

Ectopic Beats ◽

Atrial Rhythm ◽

Pathophysiologic Mechanisms

Multifocal atrial tachycardia (MAT) is an atrial arrhythmia arising in the left or right atrium, or both, with multiple different P wave morphologies (at least three), with an atrial rate usually faster than 100 min−1. The atrial rhythm may be irregular; however, the defining difference between MAT and atrial fibrillation is the presence of a P wave prior to each QRS complex in MAT (but the absence of P waves in atrial fibrillation). MAT may be compared to sinus rhythm with very frequent polymorphic atrial ectopic beats, and in fact similar pathophysiologic mechanisms underlie both conditions; thus, differentiating one from the other may be difficult—the principle difference is the lack of a single dominant sinus pacemaker in MAT.

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LO018: The utility of ECG characteristics as prognostic markers in pulseless electrical activity arrests: a retrospective observational cohort study

CJEM ◽

10.1017/cem.2016.55 ◽

2016 ◽

Vol 18 (S1) ◽

pp. S36-S36

Author(s):

M. Ho ◽

M. Gatien ◽

C. Vaillancourt ◽

V. Whitham ◽

I.G. Stiell

Keyword(s):

Electrical Activity ◽

Pulseless Electrical Activity ◽

Multivariate Regression Analysis ◽

Spontaneous Circulation ◽

Qrs Complex ◽

P Waves ◽

Initial Rhythm ◽

Observational Cohort ◽

Kappa Agreement ◽

The Impact

Introduction: Compared to pseudo-pulseless electrical activity (PEA with myocardial contractions present), true PEA is hypothesized to carry a poorer prognosis and to show bradycardia and a wide QRS complex on ECG. Our objective was to study the predictive potential of ECG characteristics on survival to hospital discharge (SHD) for out-of-hospital cardiac arrest (OHCA) patients with PEA initial rhythm. Methods: We studied a cohort of OHCA patients prospectively enrolled between Sept. 2007 and Oct. 2009 at the Ottawa/OPALS site (13 cities, 7 EMS, and 6 Fire services) of the ROC PRIMED study. We included adult (≥ 18) non-traumatic OHCA with PEA initial rhythm where resuscitation was attempted, and for which ECG characteristics were available. We measured mean heart rate (HR), mean QRS interval, and presence of P waves (each with kappa agreement) using the first six QRS complex available. We report patient and system characteristics using descriptive statistics and determined the impact of ECG characteristics (HR, QRS width, P waves) on return of spontaneous circulation (ROSC) and SHD using multivariate regression analysis. Results: Demographics of 332 included cases were: mean age 71.7; male 58.4%; home residence 76.5%; bystander witnessed 56.3%; bystander CPR 28.5%; interval from dispatch to paramedic arrival 6min:24sec; ROSC at ED arrival 26.5%; SHD 5.4%. Survivors had higher mean HR (66.1 vs. 52.0 bpm, p=0.83; kappa=0.69) and shorter mean QRS intervals (108.3 vs. 129.6 ms, p=0.01; kappa=0.74) compared to non-survivors. Presence of p waves could not reliably be ascertained (kappa=0.35). Predictors of ROSC were: ALS paramedic on scene (AdjOR=8.90, 95%CI 1.11-71.41; p=0.04), successful intubation (AdjOR=3.35, 1.75-6.39; p=0.0002), and use of atropine (AdjOR=0.27, 0.14 - 0.50; p<0.0001). Predictors of survival were: location of arrest (AdjOR=1.49, 1.11 - 1.99; p=0.007), and use of atropine (AdjOR=0.06, 0.02-0.22; p<0.0001). Despite various cutoff explorations, ECG characteristics were not predictive of ROSC or survival in multivariate analyses. Survivors had HR as low as 6 bpm and QRS as wide as 357 ms. Conclusion: Early ECG characteristics could not predict ROSC or SHD in a population of OHCA PEA victims, and should not be used to terminate resuscitation efforts. Atropine administration was consistently associated with decreased likelihood of ROSC and survival.

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Atrioventricular nodal re-entrant tachycardia

10.1093/med/9780199568741.003.0114 ◽

2018 ◽

Author(s):

Michael Jones ◽

Norman Qureshi ◽

Kim Rajappan

Keyword(s):

Supraventricular Tachycardia ◽

Qrs Complex ◽

P Waves ◽

Narrow Qrs ◽

Narrow Qrs Complex

Atrioventricular nodal re-entrant tachycardia (abbreviated as AVNRT) is one of the five subtypes of supraventricular tachycardia, manifesting most commonly as a regular, narrow QRS complex tachycardia, rate 150–250 min−1 (usually 160–180 min−1), occurring paroxysmally, with P waves either not apparent, or seen to follow the QRS complexes.

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Irregular narrow QRS complex tachycardia with intermittent P‐waves linked to two QRS complexes: What is the mechanism?

Journal of Cardiovascular Electrophysiology ◽

10.1111/jce.13940 ◽

2019 ◽

Vol 30 (8) ◽

pp. 1384-1387

Author(s):

Chengye Di ◽

Yansheng Ding ◽

Peng Gao ◽

Qun Wang ◽

Yanxi Wu ◽

...

Keyword(s):

Qrs Complex ◽

P Waves ◽

Narrow Qrs ◽

Narrow Qrs Complex

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CardiacWave

Proceedings of the ACM on Interactive Mobile Wearable and Ubiquitous Technologies ◽

10.1145/3478127 ◽

2021 ◽

Vol 5 (3) ◽

pp. 1-26

Author(s):

Chenhan Xu ◽

Huining Li ◽

Zhengxiong Li ◽

Hanbin Zhang ◽

Aditya Singh Rathore ◽

...

Keyword(s):

Vital Signs ◽

Cardiac Activity ◽

Ground Truth ◽

P Wave ◽

Qrs Complex ◽

High Definition ◽

Full Spectrum ◽

P Waves ◽

High Positive Correlation ◽

Heart Monitoring

Using wireless signals to monitor human vital signs, especially heartbeat information, has been intensively studied in the past decade. This non-contact sensing modality can drive various applications from cardiac health, sleep, and emotion management. Under the circumstance of the COVID-19 pandemic, non-contact heart monitoring receives increasingly market demands. However, existing wireless heart monitoring schemes can only detect limited heart activities, such as heart rate, fiducial points, and Seismocardiography (SCG)-like information. In this paper, we present CardiacWave to enable a non-contact high-definition heart monitoring. CardiacWave can provide a full spectrum of Electrocardiogram (ECG)-like heart activities, including the details of P-wave, T-wave, and QRS complex. Specifically, CardiacWave is built upon the Cardiac-mmWave scattering effect (CaSE), which is a variable frequency response of the cardiac electromagnetic field under the mmWave interrogation. The CardiacWave design consists of a noise-resistant sensing scheme to interrogate CaSE and a cardiac activity profiling module for extracting cardiac electrical activities from the interrogation response. Our experiments show that the CardiacWave-induced ECG measures have a high positive correlation with the heart activity ground truth (i.e., measurements from a medical-grade instrument). The timing difference of P-waves, T-waves, and QRS complex is 0.67%, 0.71%, and 0.49%, respectively, and a mean cardiac event difference is within a delay of 5.3 milliseconds. These results indicate that CaridacWave offers high-fidelity and integral heart clinical characteristics. Furthermore, we evaluate the CardiacWave system with participants under various conditions, including heart and breath rates, ages, and heart habits (e.g., tobacco use).

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