Related Experiment Video

Updated: Feb 3, 2026

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
12:45

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing

Published on: December 11, 2017

11.0K

Baseline Prolonged PR Interval and Outcome of Cardiac Resynchronization Therapy: A Systematic Review and

Pattara Rattanawong1, Narut Prasitlumkum1, Tanawan Riangwiwat1

  • 1University of Hawaii Internal Medicine Residency Program, Honolulu, Havaí - EUA.

Arquivos Brasileiros De Cardiologia
|October 18, 2018
PubMed

Insights

A prolonged PR interval in cardiac resynchronization therapy (CRT) patients predicts worse outcomes. This meta-analysis confirms that a longer PR interval is linked to increased mortality and heart failure hospitalizations in CRT recipients.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Statistics

Background:

  • Baseline prolonged PR interval is increasingly recognized as a potential negative prognostic marker in cardiac resynchronization therapy (CRT).
  • Existing literature suggests an association, but a comprehensive systematic review and meta-analysis is lacking.

Purpose of the Study:

  • To systematically review and meta-analyze existing studies to assess the association between baseline prolonged PR interval and adverse outcomes in patients undergoing CRT.
  • To quantify the risk of all-cause mortality, heart failure hospitalization, and composite outcomes associated with a prolonged PR interval in CRT patients.

Main Methods:

  • A systematic literature search was conducted in MEDLINE and EMBASE databases up to March 2017.
  • Included studies were prospective or retrospective cohort studies comparing outcomes in CRT patients with prolonged PR interval (>200 msec) versus normal PR interval.
  • Data were pooled using random-effects meta-analysis to calculate pooled risk ratios and 95% confidence intervals.

Main Results:

  • Six studies involving 17,432 normal PR and 4,278 prolonged PR for mortality were analyzed.
  • Prolonged PR interval was significantly associated with increased risk of all-cause mortality (RR=1.34, 95% CI: 1.08-1.67).
  • Significant associations were also found for heart failure hospitalization (RR=1.30, 95% CI: 1.16-1.45) and composite outcomes (RR=1.21, 95% CI: 1.13-1.30).

Conclusions:

  • The findings support the hypothesis that a baseline prolonged PR interval is an independent predictor of adverse outcomes in CRT patients.
  • This meta-analysis highlights the clinical significance of baseline PR interval in stratifying risk for CRT recipients.
  • Routine assessment of PR interval may aid in patient selection and risk stratification for CRT.
Abstract

More Related Videos

Meta-Analysis of the Effectiveness and Safety of Shugan Jieyu Capsules for the Treatment of Insomnia04:34

Meta-Analysis of the Effectiveness and Safety of Shugan Jieyu Capsules for the Treatment of Insomnia

Published on: February 17, 2023

1.6K
Author Spotlight: Evaluating the Adjuvant Efficacy and Safety of Angong Niuhuang Pill in Viral Encephalitis Treatment08:36

Author Spotlight: Evaluating the Adjuvant Efficacy and Safety of Angong Niuhuang Pill in Viral Encephalitis Treatment

Published on: April 19, 2024

1.2K

Related Concept Videos

Prediction Intervals01:03

Prediction Intervals

The interval estimate of any variable is known as the prediction interval. It helps decide if a point estimate is dependable.
However, the point estimate is most likely not the exact value of the population parameter, but close to it. After calculating point estimates, we construct interval estimates, called confidence intervals or prediction intervals. This prediction interval comprises a range of values unlike the point estimate and is a better predictor of the observed sample value, y. 
3.4K
Review and Preview01:10

Review and Preview

In statistics, several tools are used to interpret the data. Measures of central tendency represent the characteristics of the data, such as mean, median, and mode. Additionally, measures of variance like standard deviation and range are used to find the spread of data from the mean. Relative standing measures the distance between data locations. Commonly used measures of relative standings are percentile, z score, and quartiles.
Percentiles are a type of fractile that partition data into...
8.4K
Review and Preview01:13

Review and Preview

Data are individual items of information obtained from a population or sample. Data may be classified as qualitative (categorical), quantitative continuous, or quantitative discrete. Because it is not practical to measure the entire population in a study, researchers use samples to represent the population. A random sample is a representative group from the population chosen by using a method that gives each individual in the population an equal chance of being included in the sample. Random...
11.3K
Confidence Intervals01:21

Confidence Intervals

An unbiased point estimate is often insufficient to predict a population estimate, such as population mean or population proportion. In this scenario, a confidence interval is used. A confidence interval is an estimate similar to a  sample proportion. However, unlike the point estimate which is a single value, the confidence interval  contains a range of values. These values have lower and upper limits, known as confidence limits, and can be designated as L1 and L2, respectively.
A...
10.7K
Predicting Reaction Outcomes02:24

Predicting Reaction Outcomes

Kinetics describes the rate and path by which a reaction occurs. In contrast, thermodynamics deals with state functions and describes the properties, behavior, and components of a system. It is not concerned with the path taken by the process and cannot address the rate at which a reaction occurs. Although it does provide information about what can happen during a reaction process, it does not describe the detailed steps of what appears on an atomic or a molecular level. On the other hand,...
10.8K
Random and Systematic Errors01:20

Random and Systematic Errors

Scientists always try their best to record measurements with the utmost accuracy and precision. However, sometimes errors do occur. These errors can be random or systematic. Random errors are observed due to the inconsistency or fluctuation in the measurement process, or variations in the quantity itself that is being measured. Such errors fluctuate from being greater than or less than the true value in repeated measurements. Consider a scientist measuring the length of an earthworm using a...
14.9K