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Brugada Criteria
Brugada Criteria
Brugada Criteria
Brugada Criteria
Brugada Criteria
Brugada Criteria
Brugada Criteria
Brugada Criteria
Brugada Criteria
Brugada Criteria
Brugada Criteria
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Brugada Criteria

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  • 1. 1649 A New Approach to the Differential Diagnosis of a Regular Tachycardia With a Wide QRS Complex Pedro Brugada, MD; Josep Brugada, MD; Lluis Mont, MD; Joep Smeets, MD; and Erik W. Andries, MD Background. In the differential diagnosis of a tachycardia with a wide QRS complex (.0.12 second) diagnostic mistakes are frequent. Therefore, we investigated the reasons for failure of presently available criteria, and we identified new, simpler criteria and incorporated them in a stepwise approach that provides better sensitivity and specificity for making a correct diagnosis. Methods and Results. A prospective analysis revealed that current criteria had a poor specificity for the differential diagnosis. The value of four new criteria incorporated in a stepwise approach was prospectively analyzed in a total of 554 tachycardias with a widened QRS complex (384 ventricular and 170 supraventricular). The sensitivity of the four consecu- tive steps was 0.987, and the specificity was 0.965. Conclusions. Current criteria for the differential diagnosis between supraventricular tachy- cardia with aberrant conduction and ventricular tachycardia are frequently absent or suggest the wrong diagnosis. The absence of an RS complex in all precordial leads is easily recognizable and highly specific for the diagnosis of ventricular tachycardia. When an RS complex is present in one or more precordial leads, an RS interval of more than 100 msec is highly specific for ventricular tachycardia. This new stepwise approach may prevent diagnostic mistakes. (Circulation 1991;83:1649-1659) T he differential diagnosis of tachycardias on the the reasons for wrong diagnoses are unclear, lack of 12-lead electrocardiogram is not merely an knowledge of current criteria for the differential electrocardiographic exercise. When the diagnosis does not seem to be one; rather, such QRS complex during tachycardia has a normal mor- mistakes seem to be the result of the way the criteria phology, axis, and duration, the diagnosis of su- are applied or interpreted.8-10 praventricular tachycardia is easily made. Fre- The purpose of this study was twofold. On the quently, however, supraventricular tachycardias may one hand, we sought the reasons for failure of have an aberrant intraventricular conduction and a currently available criteria to provide a correct wide (>0.12 second) QRS complex. In this case, diagnosis by prospectively analyzing these criteria differentiating between supraventricular tachycardia in a series of tachycardias with a wide QRS com- with aberrant conduction (SVT) and ventricular tachy- plex. On the other hand, we sought new and simpler cardia (VT) may become difficult.' criteria and incorporated them in a stepwise ap- Even though several criteria have been proposed proach to make the differential diagnosis simpler, to help in the differential diagnosis,2-7 mistakes are more decisive, and more accurate. nevertheless frequently made.8-10 Not infrequently, these mistakes have led to wrong therapeutic deci- Methods sions with fatal or almost fatal outcomes. Although In the first part of the study, presently available criteria for differentiating between SVT with aber- From the Cardiovascular Center (P.B., L.M., E.W.A.), Post- graduate School of Cardiology, OLV Hospital, Aalst, Belgium, and rant conduction and VT were prospectively analyzed the Departments of Physiology (J.B.) and Cardiology (J.S.), Uni- in 236 tachycardias with a wide QRS complex. There versity of Limburg, Maastricht, The Netherlands. were 172 VTs and 64 SVTs with aberrant conduction Address for correspondence: Pedro Brugada, MD, Professor of with electrophysiological proven mechanism. Com- Cardiology, Cardiovascular Center, Postgraduate School of Cardi- ology, OLV Hospital, Moorselbaan 164, B-9300, Aalst, Belgium. plete 12-lead electrocardiograms were available for Received September 5, 1990; revision accepted January 8, 1991. all patients who were not receiving antiarrhythmic
  • 2. 1650 Circulation Vol 83, No 5 May 1991 TABLE 1. Morphology Criteria in This Study for Ventricular Tachycardia Sensitivity Specificity Predictive SVT VT SN SP +Value -Value Tachycardia with a right bundle branch block-like QRS Lead V, Monophasic R 11/69 39/65 0.60 0.84 0.78 0.69t QR or RS 1/69 20/65 0.30 0.98 0.95 0.60t Triphasic 57/69 6/65 0.82 0.91 0.90 0.834 Lead V6 R to S ratio <1 4/69 27/65 0.41 0.94 0.87 0.63t QS or QR 0/69 19/65 0.29 1.0 1.0 0.60t Monophasic R 0/69 1/65 0.01 1.0 1.0 0.52t Triphasic 44/69 3/65 0.64 0.95 0.93 0.714 R to S ratio >1 21/69 15/65 0.30 0.76 0.58 0.514 Tachycardia with a left bundle branch block-like QRS Lead V, or V2 Any of following:* R >30 msec, >60 msec to nadir S, notched S 3/24 91/91 1.0 0.89 0.96* Lead V6 QR or QS 0/31 6/35 0.17 1.0 1.0 0.52* Monophasic R 31/31 29/35 1.0 0.17 0.51 1.0t Data obtained from References 5 and 6. *Including any Q wave in lead V6. tValues for the diagnosis of VT. *Values for the diagnosis of SVT with aberrant conductior SVT, supraventricular tachycardia; VT, ventricular tach +Value, predictive positive value; -Value, predictive negative value; R to S ratio, ratio of R wave to S v drugs. Electrocardiograms were analyzed at a paper which favors the diagnosis of VT,45 and 4) morphol- speed of 25 mm/sec as usual in clinical practice. ogy criteria favoring the diagnosis of VT when the Current criteria analyzed included 1) a left axis of QRS complex had a right2-5,7 or a left bundle branch the QRS complex in the frontal plane, which favors block-like6 morphology. the diagnosis of VT,4.5 2) the presence of atrioven- Particularly important during the first part of the tricular dissociation, which favors the diagnosis of study were the recent observations by Kindwall et al.6 VT,2-7 3) a QRS complex longer than 0.14 second, These investigators reported that an interval between TABLE 2. Presence of Atrioventricular Dissociation, Left Axis, and Duration of the QRS Complex in 236 Prospectively Analyzed Tachyeardias With a Widened QRS Complex AV dissociation Left axis QRS> 140 msec n n ' 1n n % SVT-RB 43 0 0 3 10 7 17 SVT-LB 21 0 0 12 57 8 38 All SVT 64 0 0 15 23 15 23 VT-RB 97 18 19 63 65 73 75 VT-LB 75 19 25 57 76 63 84 All VT 172 37 21 120 70 136 79 Diagnosis of VT SN 0.21 0.70 0.79 SP 1.0 0.76 0.72 Predictive + value 1.0 0.89 0.90 Predictive - value 0.32 0.48 0.52 QRS complex >0.12 second. AV, atrioventricular; SVT-RB, supraventricular tachycardia with right bundle branch block aberrant conduction; SVT-LB, supraventricular tachycardia with left bundle branch block aberrant conduction; VT-RB, ventricular tachycardia with a right bundle branch block-like QRS complex; VT-LB, ventricular tachycardia with a left bundle branch block-like QRS complex; + value, predictive positive value; - value, predictive negative value.
  • 3. Brugada et al Differential Diagnosis of Tachycardias 1651 ABSENCE OF AN RS COMPLEX IN ALL PRECORDIAL LEADS? TABLE 3. Classic Morphology Criteria in 236 Prospectively Ana- lyzed Tachycardias With a Widened QRS Complex YES 0o Morphology criteria present in leads /T NEXT QUESTION V1,2 and V1,2 V6 V6 None n n % n % n % n % R TO S WTERVAL >100 MS IN ONE PRECORDIAL LEAD? SVT-RB 43 35 81 35 81 28 65 1 2 YES NO SVT-LB 21 18 86 13 62 12 57 2 10 VYT XT QUESTION All SVT 64 53 83 48 75 40 62 3 4 VT-RB 97 81 83 75 77 64 66 5 5 VT-LB 75 63 84 47 62 41 55 6 8 ATRVENTRICULAR DISSOCIATION? All VT 172 144 84 122 71 105 61 11 6 YES No QRS complex .0.12 second. VT NXT CKESTION SVT-RB, supraventricular tachycardia with right bundle branch block aberrant conduction; SVT-LB, supraventricular tachycardia with left bundle branch block aberrant conduction; VT-RB, ven- tricular tachycardia with a right bundle branch block-like QRS MORHLG CRITERIA FOR VT PRESENT BOTH IN PRECORDIAL LEADS Vl-2 AND VS? complex; VT-LB, ventricular tachycardia with a left bundle branch block-like QRS complex. VT SVT WITH AIBERRANT CONDUCTIO FIGURE 1. Algorithm for diagnosis of a tachycardia with a recordings, such as aortic pressure, were available to widened QRS complex. When an RS complex cannot be them. The two observers were not asked to give a identified in any precordial lead, the diagnosis of ventricular diagnosis but were asked 1) to determine whether an tachycardia (VT) is made. If an RS complex is present in one RS complex was present in at least one precordial or more precordial leads, the longest RS interval is measured. lead, 2) to measure the longest RS interval in any If the RS interval is longer than 100 msec, the diagnosis of VT precordial lead with an RS complex, 3) to determine is made. If shorter than 100 msec, the next step of the whether atrioventricular dissociation was present, and 4) to decide whether both leads V1 and V6 algorithm is considered: whether atrioventricular dissociation fulfilled classic criteria for ventricular tachycardia. is present. If present, the diagnosis of VT is made. If absent, The observers were not aware of the diagnosis, and the morphology criteria for VT are analyzed in leads V, and the four steps were used in the following way: 1) If V6. If both leads fulfill the criteria for VT, the diagnosis of VT the RS complex was not present in at least one is made. If not, the diagnosis of supraventricular tachycardia precordial lead, the diagnosis of VT was noted, and (SVT) with aberrant conduction is made by exclusion of VT. further analysis was stopped. 2) If an RS complex was present with an RS interval of more than 100 msec, the onset of the R wave to the deepest part of the S the diagnosis of VT was noted, and analysis was wave in lead V, or V2 of more than 60 msec in a left stopped. 3) If atrioventricular dissociation was diag- bundle branch block-like wide QRS complex tachy- nosed, the diagnosis of VT was made, and analysis cardia suggested the diagnosis of VT. We hypothe- was stopped. 4) If the tachycardia fulfilled the mor- sized that measurement of the intrinsic deflection in phology criteria for VT in leads V1 and V6, the any unipolar precordial lead with a clear RS complex diagnosis of VT was made. Table 1 summarizes the should be helpful in differentiating between VT and morphology criteria used. This analysis by the two SVT with aberrant conduction irrespective of the observers was, therefore, a stepwise approach. When morphology of the arrhythmia. Therefore, data were a positive diagnosis of VT was made at any step, the prospectively collected on two aspects of the arrhyth- observer was asked to stop analysis. When all four mia during the first part of the study: 1) whether an steps had been undertaken and had been answered RS complex was present in at least one precordial negatively, the diagnosis of SVT with aberrant con- lead, and 2) the length of the longest interval in any duction was made by exclusion of VT. precordial lead from the beginning of the R wave to Figure 1 summarizes the steps in the diagnosis. the deepest part of the S wave when an RS complex Observer 1 analyzed 329 tachycardias with a wide was present in one or more precordial leads. QRS complex (232 VTs and 97 SVTs with aberrant Based on the results of the first part of the study, conduction). Observer 2 analyzed 225 tachycardias the second part was undertaken prospectively. Two with a wide QRS complex (152 VTs and 73 SVTs independent observers unaware of the diagnosis an- with aberrant conduction). Because the tachycardias alyzed 554 wide QRS complex tachycardias. In all analyzed were not the same, no consideration was cases, the diagnosis of these tachycardias was proven made of possible interobserver variability in the electrophysiologically. The observers were given diagnosis. As will be described, 11 of 554 tachycar- complete 12-lead electrocardiograms during tachy- dias (2%) were misclassified. Further analysis of cardia recorded at a paper speed of 25 mm/sec. No these 11 tachycardias was undertaken later to assess endocavitary or esophageal electrograms or other reasons and possible corrections of misdiagnosis.
  • 4. .> f .e^+gzop'D>rsc=_,a-.b Qit~ c: 'gs-.J+,6,*ni.^-'_,'S,+:Xe<-4q.;si1-,:{.F$*.^<5i+-,. 1652 t>_- w[S_-|.;.+as F_SF. Circulation Vol 83, No S May 1991 - __ - 1. P > i- z > _--+--- 4- e R 2 t t _k o z ,, / 'i t- 4 ': ..L t-.__ r ,L -- --*----- f: ' -: J :, R5 i4 CA w- O = t: -_ cn c) -G < t - C -> C _ T5,-i- ,<<? *t Q 2 j _v .; e. . . _ _ .s UE %j . ' C.7 =' .. S > * Cs - C _-s .. - T-ts C... C14 ::>£ :< g _r * n / =S % .. . . S .. _> a .f - 1 ..5 CS C d' ' ( S L ;. _F
  • 5. Brugada et al Differential Diagnosis of Tachycardias 1653 B with right bundle branch block aberrant conduction. Similar findings were also reported by Kindwall et a16 in tachycardias with a left bundle branch blocklike QRS complex. When the complete 12-lead electrocardio- gram was analyzed, a duration of the QRS complex of more than 0.14 second was far from a rarity in SVTs with aberrant conduction. Similar observations were previously reported by Akhtar et al. These two criteria would have favored the diagnosis of VT. Atrioventric- ular dissociation was not present in any SVT, however; although 100% specific for the diagnosis of VT, it was seen in only 21 % of the VTs. This incidence of atriov- avi entricular dissociation is similar to the incidence re- ported in other studies.45,7 The morphology criteria for the corresponding tachycardia (SVT or VT) were fre- avf quently present in lead V, or V6. However, 4% of the V1 V,' A~~~~~ SVTs and 6% of the VTs did not fulfill the criteria for their diagnosis in any lead (Figures 2 and 3). More important, more than one third of the SVTs and VTs did not fulfill the morphology criteria in lead V1 and V4 lead V6. That is, although one lead suggested the diagnosis of VT, the other lead suggested the diagnosis of SVT, or vice versa (Figure 4). Akhtar et a17 also V3 / vIjiI previously discussed these points. Thus, discordance in V5 ~ ~ morphology criteria occurred frequently, and criteria .{ i f suggesting VT, such as a left axis of the QRS complex V6 in the frontal plane or a duration of the QRS complex of 0.14 second or more, were frequently present in SVT with aberrant conduction. 1/ ! t ~%/i RS Complex and Interval in the Precordial Leads During this first part of the study, an RS complex was present in at least one precordial lead in all SVTs with aberrant conduction. However, 45 of 172 (26%) FIGURE 3. Panel A: Twelve-lead electrocardiograms show VTs did not have an RS complex in any precordial a ventricular tachycardia (VT) with morphology criteria lead (Figure 5). suggesting supraventricular tachycardia (SVT) with aberrant The interval from the onset of the R wave to the conduction. Note the triphasic QRS complex in lead V, and deepest part of the S wave was measured, irrespec- the R to S wave ratio of more than 1 in lead V6. Right axis tive of the morphology of the tachycardia, in all of the QRS complex is in the frontal plane (not helpful in the tachycardias showing an RS complex in at least one differential diagnosis), and atnioventricular dissociation is precordial lead. When an RS complex was present in absent. Only the duration of the QRS complex can suggest more than one precordial lead, the longest RS inter- the diagnosis of VT, but most criteria suggest SVT with val in any precordial lead was measured. Figure 6 aberrant conduction. Panel B: Twelve-lead electrocardio- illustrates the measurement of this interval, and grams show another VT with a triphasic QRS complex in leads V, and V6, also a right axis in the frontal plane, and a Table 4 lists the distribution of this interval in the different tachycardias. As shown, an RS interval QRS duration of 120 msec. Atrioventricular dissociation is longer than 100 msec was not observed in any SVT only recognizable to the expert eye in lead avr. Paper speed with aberrant conduction. About half of the VTs was 25 mm/sec. having an RS complex in at least one precordial lead had an RS interval of 100 msec or less (61 of 127, 48%), and the other half (52%) of the VTs had an RS Results interval of more than 100 msec. From these observa- Analysis of Current Criteria tions, we concluded that the absence of an RS complex in all precordial leads or an RS interval of Tables 2 and 3 summarize findings in the 236 tachy- more than 100 msec in any precordial lead when an cardias with a wide ORS complex that were analyzed. RS complex was present were each 100% specific for A left axis of the ORS complex in the frontal plane the diagnosis of VT. From the first part of the study, frequently occurred in SVTs with left bundle branch we also concluded that atrioventricular dissociation block aberrant conduction and less frequently in SVTs was 100% specific for the diagnosis of VT.
  • 6. f*us--'.,t;v*JhtO0?_F}5r<P,.+^:<we@+M'2A{NjsPg -i>842J0rs$dtjXS_S}1b.NA+5s';g*^Eevu,afyz4sW-(X:br$.j;+_t 2|tISf.*-F'leTiw;,oGs_^N7S-g.+a v-+*Z.F-i;'SsPtEX>;2F,5.HJ.l-iafteFs,g__¢;SoeIL -tse{i_'.,+ M;tb'm.fPwsiAM-_s4txjt.,sS>DPe -:.*e;ts'5.- _:A$9,.XF, C_et_,.''4 5*_,.;-IiyM.] 1654 Circulation Vol 83, No 5 May 1991 0n _ wS it L ,. .. 4 ., - } -+ fie '- OS- 2 sk F- + :s, _ M - _44- .;44-- H_, P i. . S. P..< ...+ ... E. .4 *<;C si .F....>. .+4.. ..1- Ns; CR -- .L;. t-- *t .. N . f '44E: - K. X- F Z0 A- -t *>_ 6 -A, i= 88_P_ _ ' P -0 _S_' J,. AWS_ o--re -; ., a - ., >> m^n' .H 1'i- T_|*_ 4 ; *1 n5. + _T-, r- +--- ad-< l s + ...w5 tt. -- er T. tv ----i *is t- 4-- . .. ,< | t- - jg t *j _. J - r ^- i.- -: .e '. 5 t {'. Q kr0 m - _^,.- -- .-- - ^ s; 0n / f J----- 2 r s aST 0- -4-N tS-- lls -oN 5 .F., .N .l .t. se t- *-! *-S- *- Ms e -v) H t - o;Le -N 4 b .. a tz ,_ _,> {d te, t- t t t--is z *-m-- -, (-- t-si :' S , t: *r. ._.. >v-- r- s i.i. .5-.1_ ^FF .. -a. - -+ks- 1.. .__W. .. _, _ /j_ A, ,_t JU_e __ s __-*oo P__j._ rr P_-+_ b_ . a. _ St F _ _, t. k ] 29-- b*<; - 9<--t -, A--,-- >1Ns--Xao zT556- ji L ....p; (. ; ;.. t ..' ....S ...rs + v ..} 4e o .o Ms - - = QC LL C4- Ct
  • 7. Brugada et al Differential Diagnosis of Tachycardias 1655 A B C D aE 11 IuVAVA~/ avr / t/ Vv'9 0F i9 'v a avf Vi WArAAA, ~V' v ii A V2;X'>4~X """ V5v#vrvtv r AV4 / FIGURE 5. Twelve-lead electrocardiograms showing ventricular tachycardias without RS complexes in any precordial lead. This finding is 100% specific for the diagnosis of ventricular tachycardia. Only QS, QR, or monophasic R complexes are observed. TABLE 4. Distribution and Means for RS Intervals in the Precordial Lead With the Longest RS Interval, Longest Duration of the QRS Complex in That Lead, and Longest Duration of the QRS Complex in Any Lead in 236 Tachycardias With a Widened QRS Complex RS interval (msec) n <40 <60 <80 <100 <120 <140 <160 <180 <200 SVT-RB 43 7 14 14 8 0 0 0 0 0 SVT-LB 21 2 9 8 2 0 0 0 0 0 All SVT 64 9 23 22 10 0 0 0 0 0 VT-RB 66 2 2 12 13 23 5 8 1 0 VT-LB 61 0 0 11 21 14 10 3 2 0 All VT 127* 2 2 23 34 37 15 11 3 0 RS interval (msec) < 100 msec > 100 msec n % All SVT 64/64 100 0/64 0 All VT 61/127 52 66/127 48 Mean Mean L QRS (msec) RS QRS Mean Range SVT-RB 66 126 136 120-200 SVT-LB 65 132 143 120-160 VT-RB 110 165 170 120-300 VT-LB i11 168 180 120-260 QRS complex >0.12 second. SVT-RB, supraventricular tachycardia with right bundle branch block aberrant conduction; SVT-LB, supraventric- ular tachycardia with left bundle branch block aberrant conduction; VT-RB, ventricular tachycardia with a right bundle branch block like QRS complex. VT-LB, ventricular tachycardia with a left bundle branch block like QRS complex; mean QRS, mean duration of the QRS complex in the lead in which the RS interval was measured; mean L QRS, mean duration of the longest QRS complex measured at any lead. *Forty~five VT did not have an RS complex in any precordial lead.
  • 8. 1656 Circulation Vol 83, No S May 1991 A N=554 (384 VT, 170 SVT WITH ABERRANCY) ABSENCE OF AN RS COLEX IN ALL PRECORDIAL LEADS? 83 YES 471 NO B ,~V R TO S INTERAL >100 MS INOEPEOIA LEA? 175 YES 296 NO ~~V4 172 VT, 3 SVT SN=.6 W=.9oa ATRIO-VENTRICULAR DISSOCIATION? YES / 237 .. iV SE.VE SN-=.82 SPff MORPHOLOGY CRITERIA FOR VT PRESENT BOTH PRECORDIAL LEADS VI-2 AND VS? R - ---- -1 / 68 YES 169 NO 65 VT, 3 SVT 164 SVT, S VT SN=.987 SP=.965 SN=.965 SP=.987 L V6; FIGURE 7. Algorithm of the diagnosis made by two observers -4 Hb in 554 tachycardias with a widened QRS complex. Number of F tachycardias classified at each step is given. Sensitivities (SN) and specificities (SP) for the diagnosis of ventricular tachyvcar- dia (VT) are also shown at each step and also for the diagnosis of supraventricular tachycardia (SVT) with aberrant FIGURE 6. Tracings from the 12-lead electrocardiogram conduction at the last step. Note that the four consecutive illustrating the measurement of the RS intervaL A ventricular criteria reached a sensitivity of 0.987 and specificity of 0. 965 a tachycardia with a right bundle branch blocklike QRS for the diagnosis of VT and of 0.965 and 0.987 for the complex is shown. An RS complex is observed in the diagnosis of SVT with aberrant conduction. precordial leads V4 to V6. S wave is, however, not sharp enough in lead V? to measure confidently an RS interval. RS tion. Three of the six SVTs were considered to have interval (enlarged in the right panel) measures 160 msec in an RS interval in at least one precordial lead that was lead V, and 70 msec in lead V6. Thus, the longest RS interval longer than 100 msec. Two of the three were misclas- is more than 100 msec and diagnostic of ventricular tachy- sified by observer 1 and one by observer 2. The three cardia. Paper speed was 25 mm/sec. other SVTs were misclassified as VTs, one by ob- server 1 and two by observer 2 because these were believed to fulfill the morphology criteria for VT in The duration of the RS interval was not dependent leads V, and V6. Three VTs were misclassified as on the duration of the QRS complex in the same lead SVTs with aberrant conduction by observer 1 and and was independent of the morphology of the tachy- two by observer 2 because after the first three steps of cardia. The correlation coefficient between duration of the analysis were answered negatively, the observers the RS interval and duration of the ORS complex in considered that these tachycardias did not fulfill the the lead where the QRS complex was measured was morphology criteria for VT in the precordial leads V, 0.0764 for SVT and 0.52 for VT (p=NS). and V6. Thus, the absence of an RS complex in the precordial leads had a specificity of 1.00 and a Prospective Analysis of the New Criteria sensitivity of 0.21 in diagnosing VT. When the second criterion (RS interval, >100 msec) was applied next, Figure 7 illustrates how the diagnosis of the tachy- the sensitivity increased to 0.66, and specificity in- cardias (of which the observers were unaware) was creased to 0.98. When the criterion of atrioventricu- made using the four new criteria. Of the 384 VTs, 379 lar dissociation was included, the sensitivity in- (98.7%) were correctly classified. Of the 170 SVTs creased to 0.82, and specificity increased to 0.98. The with aberrant conduction, 164 (96.5%) were correctly last step increased sensitivity to 0.987 and decreased classified. Therefore, the sensitivity of the four step- specificity to 0.965. wise criteria for the diagnosis of VT was 0.987, and the specificity was 0.965. Further Analysis of the 11 Misclassified Tachycardias Together, the two observers misclassified 111 tachy- The 11 misclassified tachycardias were reanalyzed cardias: five VTs and six SVTs with aberrant conduc- by three observers fully aware of currently used
  • 9. Brugada et al Differential Diagnosis of Tachycardias 1657 I C-- e tIft Wavr -fl V4 Ko ju av L... -tt -r . + + I'+l YYtVYn #>VR.f..vt v2 V5 t 5 -L £ tW - ~- - -4. - °-- 1 t__ _2 Mw 4*± lit 6 FIGURE 8. Twelve-lead electrocardiograms showing one of the 11 tachycardias with a widened QRS compleV misclassified using classic and new criteria. This is a ventricular tachycardia with a left bundle branch block-like QRS complex in which axis duration of the QRS complex, and morphology criteria all suggest the wrong diagnosis of supraventricular tachycardia with left bundle branch block aberrant conduction. New criteria also incorrectly classified this ventricular tachycardia. After reconsideration, the observers discussed whether lead V3 showed an RS complex. If lead V, was considered to have a QS complex, the correct diagnosis of ventricular tachycardia had been made in the first step using the new criteria. Note that lead V4 shows an RSR complex, not an RS complex. Because the observers could not agree whether lead V3 had a QS or RS complex, limitations of old and new criteria were accepted in this case. Paper speed was 25 mm/sec. criteria and of the new criteria. Each observer was phology patterns that suggest a different diagnosis. asked to reconsider the diagnosis on the basis of both It is understandable that morphology discordance criteria. No tachycardia could be classified correctly. may confuse the physician confronted with a tachy- An example is shown in Figure 8. cardia having wide QRS complex and may lead to an incorrect diagnosis. Discussion Another major limitation of the currently used Several investigators previously discussed the criteria is that they do not include a stepwise. limitations of currently available criteria in the decision tree-like approach. When all criteria are differential diagnosis of a tachycardia with a wid- not in agreement with a diagnosis, the physician ened QRS complex.6-10 To the experienced rhyth- does not have any further steps to help in decision mologist, the diagnosis may seem obvious even making. An algorithm with simple criteria, with when criteria show discordance or suggest different steps that render clear decisions, and with known diagnoses. However, mistakes in the diagnosis are sensitivity and specificity for each step seems highly made frequently, and therapeutic decisions based desirable. on a wrong diagnosis may have fatal or almost fatal The new criteria we developed were based on consequences.8 10 these concepts and on the observations made by This study shows that currently used criteria Kindwall et a16 in tachycardias with a left bundle favoring the diagnosis of VT are frequently found in branch block-like QRS complex. We hypothesized SVTs with aberrant conduction when a complete that the intrinsic deflection, measured from the onset 12-lead electrocardiogram is analyzed. The sensi- of the R wave to the deepest part of the S wave, tivity and specificity of the old criteria are not should be longer in VT than in SVT in any unipolar optimal. The major problem seems, however, that precordial lead having an RS morphology, irrespec- leads V, and V6 frequently show discordant mor- tive of the morphology of the tachycardia (right or
  • 10. 1658 II III avr avf Circulation Vol 83, No 5 May 1991 . L*I &< yf S fl A _ 903 AtvrlrtA t.~srArV½dV'+tM B SAtVA-t,NV%sZWtk _'rJ FIGURE 9. Twelve-lead elec- trocardiograms illustrating the value of the new criteria com- pared with old criteria in differ- ential diagnosis. Panel A: ven- tricular tachycardia (VT) in a patient with surgically corrected tetralogy of Fallot. RS complex occurs in leads V2 to V,6. 1RS interval is clearly longer than 100 msec and is diagnostic for VT. Panel B: Supraventriculartachy- cardia (SVT) with right bundle branch block aberrant conduc- tion from the same patient QRS complex is longer than 200 msec. Atrioventricular dissociation is not visible, and axis of the QRS complex in the frontal plane is of no help in the differential diag- nosis. QRS complex is triphasic in lead V,, but the R to S wave ratio is less than 1 in lead V6. Thus, old critera favor the diag- nosis of VTin this case. With the new criteria, the correct diagno- sis of SVT with right bundle branch block aberrant conduc- tion was made as follows. 1) Absence of an RS complex in precordial leads: An RS complex is in lead V6. 2) RS interval greater than 100 msec in one precordial lead: RS interval is less than 100 msec. 3) Atrioven- tricular dissociation: Not recog- nizable. 4) Morphology criteria for VTpresent in both precordial leads V, and V,: No, because lead V1 had a tnphasic complex. Thus, by excluding VT with the four steps, the correct diagnosis of SVT was made. left bundle branch block-like ORS complex). As and positively directed to the diagnosis of the type of shown in part one of this study and also in the arrhythmia. That is, if RS complex is not present in independent analysis by two observers, this hypothe- any precordial lead, the diagnosis of VT is made, and sis resulted in accurate diagnoses. During the first further analysis is stopped. If an RS complex is part of this study, we also observed that when a present, the longest RS interval in the precordial tachycardia with a wide QRS complex does not have leads is measured. If the RS interval is longer than an RS complex in at least one precordial lead the 100 msec, the diagnosis of VT is made, and the diagnosis of VT can immediately be made with 100% remaining two steps are ignored. When the RS specificity. These two criteria, combined with the interval is 100 msec or less, the third step must be criterion of atrioventricular dissociation (also highly considered, that is, whether atrioventricular dissocia- specific for VT) and with the morphology criteria for tion is present. When present, the diagnosis of VT is VT in both leads V1 and V6, had a high sensitivity and made. When absent, the morphology criteria are specificity for differentiating between VT and SVT analyzed in leads V, and V6. If both leads have a with aberrant conduction. The advantages of this stepwise approach to diag- morphology compatible with the diagnosis of VT, the nosis (Figure 1 and Figure 7) are that it is structured diagnosis of VT is made. Otherwise, the diagnosis of
  • 11. Brugada et al Differential Diagnosis of Tachycardias 1659 SVT with aberrant conduction is made by exclusion 4. Wellens HJJ, Bar FWHM, Lie KI: The value of the electro- of VT (Figure 9). cardiogram in the differential diagnosis of a tachycardia with a widened QRS complex. Am J Med 1978;64:27-33 Obviously, the correct diagnosis depends on careful 5. Wellens HJJ, Bar FW, Vanagt EJ, Brugada P, Farr6 J: The application of the four criteria. Of emphasis, only an differentiation between ventricular tachycardia and supraven- RS complex or its absence in all precordial leads is tricular tachycardia with aberrant conduction: The value of valuable for the diagnosis. Complexes with QR, QRS, the 12-lead electrocardiogram, in Wellens HJJ, Kulbertus HE QS, monophasic R, or rSR morphology are not consid- (eds): What's New in Electrocardiography? The Hague, Marti- nus Nijhoff Publishing, 1981; pp 184-199 ered RS complexes. Only when an RS interval is 6. Kindwall KE, Brown J, Josephson ME: Electrocardiographic measurable can the complex be considered an RS criteria for ventricular tachycardia in wide complex left bundle complex. branch block morphology tachycardias. Am J Cardiol 1988;61: These new criteria incorporated in a stepwise 1279-1283 7. Akhtar M, Shenasa M, Tchou PJ, Jazayeri M: Role of elec- approach may help prevent the frequent errors made trophysiologic studies in supraventricular tachycardia, in in the differential diagnosis of tachycardias with a Brugada P, Wellens HJJ (eds): Cardiac Arrhythmias: Where to wide QRS complex. Go From Here? Mount Kisco, NY, Futura Publishing Co, 1987, pp 233-242 References 8. Morady F, Bareman JM, DiCarlo LA Jr, DeBuitleir M, Krol RB, Wehr DW: A prevalent misconception regarding wide 1. Kistin AD: Problems in differentiation of ventricular arrhyth- complex tachycardias. JAMA 1985;254:2790-2792 mias with abnormal QRS. Prog Cardiovasc Dis 1966;9:1-27 9. Danney M, Camm AJ, Ward D: Misdiagnosis of chronic 2. Sandler A, Marriot HJL: The differential morphology of recurrent ventricular tachycardia. Lancet 1985;2:320-323 anomalous ventricular complexes of RBBB type in lead 10. Stewart RB, Baray GH, Greene HL: Wide complex tachycar- V,-Ventricular ectopy versus aberration. Circulation 1965;31: dia: Misdiagnosis and outcome after emergent therapy. Ann 551-556 Intem Med 1986;104:771-776 3. Marriott HJL, Sandler IA: Criteria, old and new, for differ- entiating between ectopic ventricular beats and aberrant ven- tricular conduction in the presence of atrial fibrillation. Prog KEY WORDS * ventricular tachycardia * supraventricular Cardiovasc Dis 1966;9:18-28 tachycardia * aberrant conduction * electrocardiography

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