Polymorphous ventricular tachycardia in acute myocardial infarction

Grenadier, Ehud; Alpan, Gad; N, Maor; Keidar, Shlomo; Binenboim, C; Margulies, Tamar; Palant, A

doi:10.1016/0002-9149(84)90079-1

Cited by 43 publications

(7 citation statements)

References 20 publications

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“…White and Wood 6 reported a series of four PVT patients with acute myocardial ischemia (two patients) or infarction (two patients) who presented to EMS personnel with PVT; one patient had prolongation of the QT interval, confirming the rhythm diagnosis of TdP. Concerning hospitalbased reports, Grenadier et al 21 reported nine patients with PVT-one of whom developed QT interval prolongation on the ECG prior to the VTwho were admitted to the CCU with AMI, representing a single case of TdP among 771 consecutive patients admitted with an acute coronary ischemic event. Sclarovsky et al 10 reported 34 patients with PVT, the majority of whom had QT prolongation, therefore carrying the rhythm diagnosis of TdP.…”

Section: Discussionmentioning

confidence: 95%

“…PVT has been found in patients undergoing ambulatory cardiac monitoring, 3,16,17 in survivors of out-of-hospital sudden death subsequently studied in the electrophysiologic laboratory, 16,18,19 in patients admitted to the cardiac care unit (CCU) for the treatment of acute myocardial infarction (AMI), 20,21 and in victims of out-of-hospital cardiac arrest. 6 PVT, when noted in the above situations, frequently is the initial rhythm, which then degenerates to either MVT or VF.…”

Section: Discussionmentioning

confidence: 99%

“…16,23,24 Concerning ischemic heart disease, 1% to 2% of AMI patients in the CCU experience PVT during the peri-infarction period; the majority of these patients were experiencing active coronary ischemic events at the time of dysrhythmia appearance. 20,21 Out-of-hospital patients also often have PVT; White and Wood 6 reported four cases of out-of-hospital cardiac arrest involving PVT as either the presenting rhythm or a rhythm encountered during the course of out-ofhospital resuscitation. The authors correctly suggested that PVT is a more common arrhythmia than previously thought in patients experiencing out-of-hospital SCD-particularly in the initial phases.…”

Section: Discussionmentioning

confidence: 99%

“…6,10,20,21,25 Wolfe et al 20 in their series of 11 patients with PVT related to acute ischemic heart disease, described a patient population in which traditional antiarrhythmic therapy produced a variable response. The QT interval in all cases was normal.…”

Section: Discussionmentioning

confidence: 99%

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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

Brady

DeBehnke²,

Laundrie

1999

Academic Emergency Medicine

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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-ofhospital 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 Ϯ 0.15 seconds prearrest and 0.464 Ϯ 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. Key words: ventricular tachycardia; QT interval; polymorphic ventricular tachycardia; torsades de pointes; out-of-hospital; cardiac arrest. ACADEMIC EMERGENCY MEDICINE 1999; 6:609-617 S UDDEN cardiac death (SCD) represents a significant public health problem in the United States; ventricular tachycardia (VT) and ventricular fibrillation (VF) are frequently the car- 1,2 In many cases, VF is often preceded by VT; when classified from a morphologic perspective, VT is described as either monomorphic or polymorphic.2,3 Monomorphic VT (MVT) is frequently seen, easily diagnosed, and most often treated according to well-established guidelines in the out-of-hospital set...

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Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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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

Brady

DeBehnke²,

Laundrie

1999

Academic Emergency Medicine

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“…Further pharmacological proof of a causal relation in VT due to TA and DADs should be sought; i.e., a Ca 2ϩ entry blocker might block inducible focal VT in vivo and TA in vitro. Treatment with such agents in this model could lead to trials of patients in the coronary care unit (9,29). Case reports have suggested the benefit of Ca 2ϩ antagonists (22,37) in patients with normal systolic function.…”

Section: Discussionmentioning

confidence: 99%

Triggered activity due to delayed afterdepolarizations in sites of focal origin of ischemic ventricular tachycardia

Xing

Martins

2004

American Journal of Physiology-Heart and Circulatory Physiology

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Xing, Dezhi, and James B. Martins. Triggered activity due to delayed afterdepolarizations in sites of focal origin of ischemic ventricular tachycardia. Am J Physiol Heart Circ Physiol 287: H2078 -H2084, 2004. doi:10.1152/ajpheart.00027.2004.-This study for the first time systematically evaluated the site of origin of focal ventricular tachycardia (VT) induced 1-3 h after acute coronary artery ligation in dogs. We determined whether delayed afterdepolarizations (DADs) and triggered activity (TA) are more often recorded from ischemic endocardium excised from focal sites of VT origin. A total of 145 ␣-chloralose-anesthetized dogs were studied: in 54 dogs without inducible VT, normal or ischemic endocardium was investigated in vitro; in 91 dogs, inducible VT was studied by threedimensional activation mapping, with in vitro study of 51 endocardial foci compared with 40 endocardial ischemic sites not of VT origin. Incidence of DADs (71% vs. 33%, P Ͻ 0.05) and TA (32% vs. 11%, P Ͻ 0.05) was greater in ischemic than in normal Purkinje tissues. Purkinje sites of origin of focal VT demonstrated the greatest frequency of DADs (92%, P Ͻ 0.05) and TA (75%, P Ͻ 0.05), with repetitive TA predominating. Similar results were obtained in endocardial sites of origin. Action potentials were mildly depolarized and prolonged in the focal sites of origin. These abnormalities were stable up to 2.5 h of recording. This study demonstrated that DADs and TA may underlie a majority of focal VTs in ischemic endocardium and Purkinje tissue.ventricles; myocardial infarction; endocardium SUDDEN CARDIAC DEATH is a major public health problem. Ventricular tachycardia (VT) and fibrillation (VF) are responsible for most cases of sudden cardiac death (22). The understanding of mechanisms of VT and VF in early myocardial ischemia and infarction is hampered in humans by rapidly changing substrate over the first hours, which are rarely observed in the hospital. Animal models have been studied instead (31). Although reentry has been thought to underlie early VT (25, 36) and VF, some studies have implicated focal mechanisms (1, 2, 10, 11, 25) in endocardial and Purkinje tissue (1, 2, 10). In vitro models of acute ischemia (3,20,27,32) involving Purkinje tissue have suggested that triggered activity (TA) due to delayed afterdepolarizations (DADs) may explain these focal VTs. Abnormalities that may contribute to the occurrence of these mechanisms in acute ischemia include increased free fatty acids, oxygen free radials, acidosis, and catecholamines (22). We studied our model of inducible VT (2) after acute coronary artery occlusion employing three-dimensional activation mapping to investigate the hypothesis that TA due to DADs may be found more frequently in endocardial and Purkinje tissues that were excised from sites of origin (SOOs) of focal VT. METHODSAnimal preparation. A total of 145 dogs of either gender, weighing 8 -20 kg, were studied. The protocol was approved by the University of Iowa Animal Use and Care Committee and adhered to the standards of...

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