Prevalence, therapeutic response, and outcome of ventricular tachycardia in the out-of-hospital setting

A comparison of monomorphic ventricular tachycardia, polymorphic ventricular tachycardia, and torsades de pointes

William J. Brady, Daniel J DeBehnke, Dennis Laundrie

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21 Citations (Scopus)

Abstract

Objective: To investigate out-of-hospital ventricular tachycardia (VT) cardiac arrest patients, comparing the prevalences and outcomes of the following VT subtypes among this population: monomorphic VT (MVT), polymorphic VT (PVT), and torsades de pointes (TdP, PVT with a prolonged QT interval). Methods: This was a retrospective review from a fire department- based paramedic system of nontraumatic VT cardiac arrest patients (January 1991 to December 1994) with a supraventricular perfusing rhythm (SVPR) at some time during out-of-hospital care, with a measurable QT interval. QT interval was measured from an SVPR, and corrected QT interval (QTc) was calculated and considered prolonged if > 0.45 sec. VT was classified as polymorphic or monomorphic. TdP was defined as PVT with a prolonged QT interval. Results: 196 patients were identified; six were excluded due to incomplete medical records, leaving 190 who met inclusion criteria and were used for data analysis. 117 (62%) patients had MVT, while 73 (38%) patients had PVT; of the 73 patients with PVT, 37 (51%) had normal QTc (non-TdP PVT) and 36 (49%) had prolonged QTc (TdP PVT). 97 (51%) patients had prolonged QTc (PQTc). Regardless of VT type (i.e., MVT vs PVT), 97 (51%) patients had prolonged QTc, with a mean QTc of 0.476 ± 0.15 seconds prearrest and 0.464 ± 12 seconds postarrest. Patients with PQTc were not more likely to have PVT (70 [37%] vs 76 [40%]; p = 0.705). No significant difference with respect to paramedic-witnessed arrests in each VT morphology group and each QT group was found. The overall hospital discharge rate was 28.4%. Regardless of VT type, patients had similar rates of out-of-hospital return of spontaneous circulation (ROSC) and hospital discharge; patients with PQTc were less likely to be discharged from the hospital (19.6% vs 37.6%; p = 0.01). 27.8% of TdP and 26.8% of non-TdP patients were discharged (p = 0.912). Conclusions: In this population of out-of-hospital VT arrest patients, MVT is the most common form of VT encountered; PVT and the subtype TdP are also seen in this population with approximately equal frequencies. All three rhythm types demonstrate similar responses to standard Advanced Cardiac Life Support therapy with equal rates of out-of-hospital ROSC and hospital discharge. PQTc may be a marker of poor clinical outcome in patients with out-of-hospital VT arrest.

Original languageEnglish (US)
Pages (from-to)609-617
Number of pages9
JournalAcademic Emergency Medicine
Volume6
Issue number6
DOIs
StatePublished - Jan 1 1999

Fingerprint

Torsades de Pointes
Ventricular Tachycardia
Therapeutics
Allied Health Personnel
Heart Arrest
Advanced Cardiac Life Support
Population

Keywords

  • Cardiac arrest
  • Out-of-hospital
  • Polymorphic ventricular tachycardia
  • QT interval
  • Torsades de pointes
  • Ventricular tachycardia

ASJC Scopus subject areas

  • Emergency Medicine

Cite this

@article{c9584ef1ec564543b0f650578a80633f,
title = "Prevalence, therapeutic response, and outcome of ventricular tachycardia in the out-of-hospital setting: A comparison of monomorphic ventricular tachycardia, polymorphic ventricular tachycardia, and torsades de pointes",
abstract = "Objective: To investigate out-of-hospital ventricular tachycardia (VT) cardiac arrest patients, comparing the prevalences and outcomes of the following VT subtypes among this population: monomorphic VT (MVT), polymorphic VT (PVT), and torsades de pointes (TdP, PVT with a prolonged QT interval). Methods: This was a retrospective review from a fire department- based paramedic system of nontraumatic VT cardiac arrest patients (January 1991 to December 1994) with a supraventricular perfusing rhythm (SVPR) at some time during out-of-hospital care, with a measurable QT interval. QT interval was measured from an SVPR, and corrected QT interval (QTc) was calculated and considered prolonged if > 0.45 sec. VT was classified as polymorphic or monomorphic. TdP was defined as PVT with a prolonged QT interval. Results: 196 patients were identified; six were excluded due to incomplete medical records, leaving 190 who met inclusion criteria and were used for data analysis. 117 (62{\%}) patients had MVT, while 73 (38{\%}) patients had PVT; of the 73 patients with PVT, 37 (51{\%}) had normal QTc (non-TdP PVT) and 36 (49{\%}) had prolonged QTc (TdP PVT). 97 (51{\%}) patients had prolonged QTc (PQTc). Regardless of VT type (i.e., MVT vs PVT), 97 (51{\%}) patients had prolonged QTc, with a mean QTc of 0.476 ± 0.15 seconds prearrest and 0.464 ± 12 seconds postarrest. Patients with PQTc were not more likely to have PVT (70 [37{\%}] vs 76 [40{\%}]; p = 0.705). No significant difference with respect to paramedic-witnessed arrests in each VT morphology group and each QT group was found. The overall hospital discharge rate was 28.4{\%}. Regardless of VT type, patients had similar rates of out-of-hospital return of spontaneous circulation (ROSC) and hospital discharge; patients with PQTc were less likely to be discharged from the hospital (19.6{\%} vs 37.6{\%}; p = 0.01). 27.8{\%} of TdP and 26.8{\%} of non-TdP patients were discharged (p = 0.912). Conclusions: In this population of out-of-hospital VT arrest patients, MVT is the most common form of VT encountered; PVT and the subtype TdP are also seen in this population with approximately equal frequencies. All three rhythm types demonstrate similar responses to standard Advanced Cardiac Life Support therapy with equal rates of out-of-hospital ROSC and hospital discharge. PQTc may be a marker of poor clinical outcome in patients with out-of-hospital VT arrest.",
keywords = "Cardiac arrest, Out-of-hospital, Polymorphic ventricular tachycardia, QT interval, Torsades de pointes, Ventricular tachycardia",
author = "Brady, {William J.} and DeBehnke, {Daniel J} and Dennis Laundrie",
year = "1999",
month = "1",
day = "1",
doi = "10.1111/j.1553-2712.1999.tb00414.x",
language = "English (US)",
volume = "6",
pages = "609--617",
journal = "Academic Emergency Medicine",
issn = "1069-6563",
publisher = "Wiley-Blackwell",
number = "6",

}

TY - JOUR

T1 - Prevalence, therapeutic response, and outcome of ventricular tachycardia in the out-of-hospital setting

T2 - A comparison of monomorphic ventricular tachycardia, polymorphic ventricular tachycardia, and torsades de pointes

AU - Brady, William J.

AU - DeBehnke, Daniel J

AU - Laundrie, Dennis

PY - 1999/1/1

Y1 - 1999/1/1

N2 - Objective: To investigate out-of-hospital ventricular tachycardia (VT) cardiac arrest patients, comparing the prevalences and outcomes of the following VT subtypes among this population: monomorphic VT (MVT), polymorphic VT (PVT), and torsades de pointes (TdP, PVT with a prolonged QT interval). Methods: This was a retrospective review from a fire department- based paramedic system of nontraumatic VT cardiac arrest patients (January 1991 to December 1994) with a supraventricular perfusing rhythm (SVPR) at some time during out-of-hospital care, with a measurable QT interval. QT interval was measured from an SVPR, and corrected QT interval (QTc) was calculated and considered prolonged if > 0.45 sec. VT was classified as polymorphic or monomorphic. TdP was defined as PVT with a prolonged QT interval. Results: 196 patients were identified; six were excluded due to incomplete medical records, leaving 190 who met inclusion criteria and were used for data analysis. 117 (62%) patients had MVT, while 73 (38%) patients had PVT; of the 73 patients with PVT, 37 (51%) had normal QTc (non-TdP PVT) and 36 (49%) had prolonged QTc (TdP PVT). 97 (51%) patients had prolonged QTc (PQTc). Regardless of VT type (i.e., MVT vs PVT), 97 (51%) patients had prolonged QTc, with a mean QTc of 0.476 ± 0.15 seconds prearrest and 0.464 ± 12 seconds postarrest. Patients with PQTc were not more likely to have PVT (70 [37%] vs 76 [40%]; p = 0.705). No significant difference with respect to paramedic-witnessed arrests in each VT morphology group and each QT group was found. The overall hospital discharge rate was 28.4%. Regardless of VT type, patients had similar rates of out-of-hospital return of spontaneous circulation (ROSC) and hospital discharge; patients with PQTc were less likely to be discharged from the hospital (19.6% vs 37.6%; p = 0.01). 27.8% of TdP and 26.8% of non-TdP patients were discharged (p = 0.912). Conclusions: In this population of out-of-hospital VT arrest patients, MVT is the most common form of VT encountered; PVT and the subtype TdP are also seen in this population with approximately equal frequencies. All three rhythm types demonstrate similar responses to standard Advanced Cardiac Life Support therapy with equal rates of out-of-hospital ROSC and hospital discharge. PQTc may be a marker of poor clinical outcome in patients with out-of-hospital VT arrest.

AB - Objective: To investigate out-of-hospital ventricular tachycardia (VT) cardiac arrest patients, comparing the prevalences and outcomes of the following VT subtypes among this population: monomorphic VT (MVT), polymorphic VT (PVT), and torsades de pointes (TdP, PVT with a prolonged QT interval). Methods: This was a retrospective review from a fire department- based paramedic system of nontraumatic VT cardiac arrest patients (January 1991 to December 1994) with a supraventricular perfusing rhythm (SVPR) at some time during out-of-hospital care, with a measurable QT interval. QT interval was measured from an SVPR, and corrected QT interval (QTc) was calculated and considered prolonged if > 0.45 sec. VT was classified as polymorphic or monomorphic. TdP was defined as PVT with a prolonged QT interval. Results: 196 patients were identified; six were excluded due to incomplete medical records, leaving 190 who met inclusion criteria and were used for data analysis. 117 (62%) patients had MVT, while 73 (38%) patients had PVT; of the 73 patients with PVT, 37 (51%) had normal QTc (non-TdP PVT) and 36 (49%) had prolonged QTc (TdP PVT). 97 (51%) patients had prolonged QTc (PQTc). Regardless of VT type (i.e., MVT vs PVT), 97 (51%) patients had prolonged QTc, with a mean QTc of 0.476 ± 0.15 seconds prearrest and 0.464 ± 12 seconds postarrest. Patients with PQTc were not more likely to have PVT (70 [37%] vs 76 [40%]; p = 0.705). No significant difference with respect to paramedic-witnessed arrests in each VT morphology group and each QT group was found. The overall hospital discharge rate was 28.4%. Regardless of VT type, patients had similar rates of out-of-hospital return of spontaneous circulation (ROSC) and hospital discharge; patients with PQTc were less likely to be discharged from the hospital (19.6% vs 37.6%; p = 0.01). 27.8% of TdP and 26.8% of non-TdP patients were discharged (p = 0.912). Conclusions: In this population of out-of-hospital VT arrest patients, MVT is the most common form of VT encountered; PVT and the subtype TdP are also seen in this population with approximately equal frequencies. All three rhythm types demonstrate similar responses to standard Advanced Cardiac Life Support therapy with equal rates of out-of-hospital ROSC and hospital discharge. PQTc may be a marker of poor clinical outcome in patients with out-of-hospital VT arrest.

KW - Cardiac arrest

KW - Out-of-hospital

KW - Polymorphic ventricular tachycardia

KW - QT interval

KW - Torsades de pointes

KW - Ventricular tachycardia

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U2 - 10.1111/j.1553-2712.1999.tb00414.x

DO - 10.1111/j.1553-2712.1999.tb00414.x

M3 - Article

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JF - Academic Emergency Medicine

SN - 1069-6563

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