Differences of Postextrasystolic Behavior of Left Ventricular and Aortic PressuresThe recognition of muscular LVOT obstruction associated with fixed stenosis has therapeutic implications. Since a catheter within the left ventricular chamber can easily induce PVCs during left heart catheterization, the induction of this arrhythmia has been considered as the standard hemodynamic intervention for evaluation of LVOT gradients. In fact, post-PVC LVOT gradient increments (dynamic obstruction) were usually considered to be indicative of hypertrophic OCM. However, fixed stenosis in the LVOT, as in WAS, might also show a post-PVC gradient potentiation, even in the documented absence of OCM. Although post-PVC decrement of arterial pulse pressure (PP) and peak systolic aortic pressure are suggestive of OCM, some cases of \AS might also show such behavior. In view of these observations we prospectively evaluated the hemodynamic behavior of the post-PVC beat in patients with OCM and with WAS free of OCM. http://www.medicines-for-diabetes.com/

Material and Methods
Two groups of patients are defined. The first consisted of 14 patients with OCM; three males and 11 females, aged 23 to 65 years (mean age 52 years). The diagnosis was made by M-mode or twodimensional echocardiogram and left ventriculography classic criteria plus demonstration of subvalvular LVOT gradient (Table 1). All patients with OCM had a morphologically normal aortic valve, a septal to posterior wall thicknes ratio>1.5, presence of basal or postmaneuver systolic anterior motion of the mitral valve in the echocardiogram, and absence of valvular systolic aortic gradient in the hemodynamic study. Thus, associated \AS was ruled out.
In the second group were 36 patients with pure WAS, 20 males and 16 females, aged 13 to 70 years (mean age 51 years). Diagnosis was made by M-mode or two-dimensional echocardiogram, left ventriculography, and aortography plus demonstration of valvular LVOT gradient Thus, OCM and significant aortic regurgitation were ruled out Tables 2 and 3). None of the VAS patients showed echocardiographic, hemodynamic, or angiographic features of OCM. Septal-to-posterior wall thickness ratio was <1.3; systolic anterior motion of the mitral valve was not present in basal conditions and could not be induced with classic provocation maneuvers; subvalvular gradients were not detected; and systolic cavity obliteration was not present in the LV angiogram.
For basal gradient comparison with OCM, we used a subgroup of 15 patients (9 males and 6 females, aged 13 to 70 years, mean age 45 years) with nonsevere \AS (basal LVOT gradient [60 mm Hg) (Table 3). Significant coronary artery disease (stenosis 50 percent) was discarded by means of selective coronary arteriography performed in all patients with angina and in those older than 40 years.
Catheterization was performed after premedication with diazepam, 5 mg, and promethazine, 25 mg IM. Left heart catheterization was performed with an end-hole catheter suitable for LVOT gradient evaluation. In all patients, simultaneous LV and aortic pressure tracings were recorded with two Statham P23 Id transducers by means of a double-lumen catheter or transeptal and retrograde left heart catheterization. Informed consent was obtained from all patients.
The following parameters were analyzed in baseline and post-PVC conditions: RR interval, peak LVSI peak ASP, aortic PP, and peak systolic ^VG. All post-PVC parameters were analyzed in the first beat after one or two consecutive PVCs that followed at least four stable sinus beats, with a full compensatory pause. PVCs were induced with a catheter within the LV chamber. Statistical analysis was performed by means of Students t test for unpaired quantitative data and Fishers exact test and x2 test for comparison of proportions.
Table 1—Individual Hemodynamic Parameters in the Basal and Post-PVC Condition in Patients with OCM

Case Age, yr/Sex Basal Post-PVC AAVG
RR LVSP ASP PP AVG RR LVSP ASP PP AVG
1 61/F 720 180 150 78 30 820 194 130 50 54 24
2 65/F 1,000 158 158 94 0 1,460 194 134 46 60 60
3 23/F 600 88 68 28 20 640 115 39 21 76 56
4 55/M 840 208 148 37 60 1,140 258 146 38 112 52
5 39/M 1,060 154 116 56 38 1,280 220 96 36 124 86
6 56/F 720 146 114 48 32 1,000 154 90 44 64 32
7 65/F 600 176 158 88 18 780 316 142 54 174 156
8 50/F 760 166 162 76 4 800 202 106 38 96 92
9 48/F 660 176 144 60 32 740 276 125 37 151 119
10 45/F 520 145 118 38 27 600 204 94 32 110 83
11 57/F 840 166 154 56 12 1,200 202 124 30 78 66
12 57/F 720 168 132 60 36 1,120 232 104 24 128 92
13 65/F 600 248 228 108 20 880 344 160 72 184 164
14 51/M 800 148 148 64 0 1,120 220 104 28 116 116

Table 2—Individual Hemodynamic Parameters in the Basal and Post-PVC Condition in Patients with Severe VAS

Case Age, yr/Sex Basal Post-PVC AAVG
RR LVSP ASP PP A!/G RR LVSP ASP PP AVG
1 30/F 680 182 112 40 70 1,100 220 100 48 120 50
2 59/F 520 180 103 48 77 720 240 130 76 110 33
3 43/M 800 160 80 30 80 1,140 175 75 30 100 20
4 51/M 720 212 132 68 80 1,060 240 120 76 120 40
5 46/M 680 210 100 40 110 1,040 268 88 40 180 70
6 55/M 840 173 88 38 85 1,180 212 72 34 140 55
7 64/F 500 240 112 57 128 900 270 100 50 170 42
8 39/F 600 188 108 28 80 960 200 100 56 100 20
9 62/F 850 184 100 45 84 1,120 195 85 37 110 26
10 59/M 660 190 106 48 84 1,040 240 108 68 132 48
11 68/F 720 272 108 60 164 1,360 330 114 74 216 52
12 64/M 940 155 65 20 90 1,400 180 56 20 124 34
13 65/F 560 260 140 64 120 800 308 136 88 172 52
14 52/F 700 220 128 56 92 880 268 120 64 148 56
15 43/M 760 260 180 80 80 1,100 280 168 88 112 32
16 58/M 700 250 114 54 136 880 270 102 46 168 32
17 64/F 620 236 108 58 128 800 278 108 54 170 42
18 55/M 720 250 160 98 90 1,120 288 138 72 150 60
19 65/F 610 220 116 66 104 800 260 100 50 160 56
20 47/M 760 220 132 58 88 1,080 264 100 40 164 76
21 67/M 640 216 128 70 88 1,120 266 122 72 144 56

Table 3—Individual Hemodynamic Parameters in the Basal and Post-PVC Condition in Patients with Nonsevere VAS

Case Age, yr/Sex Basal Post-PVC AAVG
RR LVSP ASP PP AVG RR LVSP ASP PP AVG
1 47/F 540 220 172 60 48 780 240 120 80 120 72
2 51/M 870 145 105 50 40 1,290 170 105 55 65 25
3 41/M 600 195 140 60 55 680 210 120 56 90 35
4 43/F 660 120 80 35 40 920 145 82 57 63 23
5 41/F 550 140 100 20 40 850 150 90 26 60 20
6 21/M 960 160 120 45 40 1,160 165 115 50 50 10
7 43/M 720 150 90 35 60 1,180 165 75 35 90 30
8 47/M 800 120 115 45 5 1,140 110 105 60 5 0
9 49/M 1,000 180 120 56 60 1,200 200 108 60 92 32
10 13/M 530 135 125 43 10 650 130 120 55 10 0
11 40/F 700 145 120 56 25 1,320 155 130 80 25 0
12 60/M 680 160 134 74 26 960 170 126 66 44 18
13 60/F 720 140 105 49 35 1,000 170 102 44 68 33
14 70/F 540 163 103 55 60 960 200 108 58 92 32
15 49/F 660 180 130 50 50 960 180 116 46 64 14

Table 4—Comparison of Collective Hemodynamic Parameters in the Basal and Post-PVC Conditions between the OCM Patients and Either the Whole Group of VAS and its Subgroup cf Nonsevere VAS

Group N BasalRR PVC RR RR BasalAVG PVC AVG AAVG(%) AAVG>75%(%) 1 ASP(%) J,PP 1(%) i PP>5(%)
OCM 14 746 ±154 977 ±255 +231±132 24± 16 109 ±41 14 (100) 14 (100) 14 (100) 13 (92) 12 (85)
All VAS 36 699 ±126 1,018 ±189 + 320 ± 125 72 ±30 110 ±50 33 (92) 3 (8)t 28 (77) 12 (33) 6 (17)§
NonsevereVAS 15 702 ±150 1,003 ±209 +301±138 39 ±17 63 ±32* 12 (80) 2 (14)4: 11 (73) 3 (20)t 1 (7) §