Characterize Left Ventricular Outflow Obstruction in Hypertrophic Cardiomyopathy: RESULTS

Posted by James

Baseline characteristics of all patient groups are indicated in Table 1. No differences in age were detected among the patient groups. More women than men were noted in the group with HCM than the group without HCM.

Echocardiography and Doppler parameters in the 15 normal subjects who underwent Amyl inhalation are shown in Table 2. No normal subject had resting systolic anterior movement of the mitral valve. Using 2 SD limits, normal Doppler peak resting left ventric­ular outflow tract velocity was established as ^2.1 m/s. The normal peak left ventricular outflow tract velocity after Amyl was established was ^2.7 m/s.

FIGURE 2. Differentiation of patient subgroups by echo-Doppler criteria. HCM = hypertrophic cardiomyopathy; AMYL = amyl ni¬trite inhalation. See text for definitions.

Based on these Doppler criteria and the echocar­diography criteria previously set forth, patients were categorized as shown in Figure 2. Of 333 patients referred for suspected HCM, 145 (44 percent) had their conditions positively diagnosed by echocardio­graphy criteria. Of these, 63 (45 percent) had resting LVOTO. Of the 82 patients without resting LVOTO, 47 (57 percent) received Amyl inhalation. Latent LVOTO was provoked in 25 (53 percent) and was absent in 22 (47 percent). The 188 patients who did not meet criteria for a diagnosis of HCM had their conditions diagnosed as follows: normal, 98 (52 percent); aortic valve disease, 35 (19 percent); left ventricular hyper­trophy of another cause, 24 (13 percent); and other cardiovascular diseases (eg, mitral valve prolapse), 31 (16 percent).
canada drugs online

Table 1—Baseline Characteristics of Patient Subsets

Croup	Age, yr	M:F
Hypertrophic cardiomyopathy	.58.4 ±15.8	53:921″
Resting obstruction	57.0 ±16.3	21:42
(n = 63)	(8-86)
Latent obstruction	58.6 ± 17.6	11:14
(n = 25)	(14-84)
No obstruction	57.6 ± 14.5	3:19
(n = 22)	(17-78)
Amyl not given	61.1 ± 16.5	18:17
(n = 35)	(15-82)
No hypertrophic cardiomyopathy	59.0 ±14.4	104:84
Normal subjects, Amyl given	63.6± 12.2	7:8
(n – 15)	(16-83)
Normal subjects, no Amyl given	.58.4 ±13.6	48:35
(n = 83)	(1-78)
Other cardiovascular diseases	.58 ±16.6	49:41
(n = 90)	(8-86)

Echocardiography and Doppler values obtained in each of the Doppler-defined hemodynamic subsets of patients with HCM are shown in Table 3. These indicate that patients with resting LVOTO, by defini­tion, had significantly higher Doppler peak outflow tract velocities, with a greater frequency and severity of systolic anterior movement of the mitral valve, greater septal and posterior wall hypertrophy, and a smaller ventricular chamber dimension than the other groups. Patients with 2-D evidence of HCM and latent LVOTO had greater septal wall hypertrophy, but less posterior wall hypertrophy, and a greater frequency and severity of systolic anterior movement of the mitral valve apparatus at rest than patients with HCM and no LVOTO. Notably, the resting left ventricular outflow velocities in normal subjects (Table 2) were equivalent to those in patients with HCM and latent LVOTO as well as those without LVOTO. Likewise, the post-Amyl velocities in normal subjects were identical to the post-Amyl velocities in patients with HCM without LVOTO.

Table 2—Echo-Doppler Barometers in Normal Subjects Receiving Amyl Nitrite

				Doppler Peak	Doppler Peak Velocity
	LVIDd,	PWTd,	SWTd,	Resting Velocity,	Following Amyl,
Subject No./Age, yr	cm	cm	cm	m/s	m/s
1/47	4.5	0.9	1.0	1.4	2.0
2/60	4.5	1.1	1.1	1.7	2.1
3/65	4.1	0.8	0.9	0.9	2.0
4/42	4.4	1.0	1.1	1.8	2.3
5/81	4.8	0.9	1.0	1.2	1.7
6/6	3.0	0.5	0.8	1.0	1.8
7/73	4.7	0.7	1.0	1.9	2.8
8/68	4.0	1.2	1.1	2.0	2.4
9/69	4.2	1.2	1.2	1.8	2.6
10/66	4.3	0.9	1.1	1.5	2.5
11/48	4.1	0.8	0.9	1.5	1.8
12/61	4.8	1.0	1.2	1.3	2.2
13/55	4.3	1.1	1.0	1.6	2.0
14/83	4.6	1.2	1.1	1.4	1.8
15/60	4.1	0.9	1.1	1.3	1.7
Mean ± 1 SD/63.6± 12.2	4.3±0.4	0.9±0.2	1.0±0.1	1.5±0.3	2.1 ±0.3
2 SD upper limit				>2.1	>2.7

Mild and transient headaches, nausea, and dizziness were frequently reported as side effects following Amyl. No patient experienced syncope, either atrial or ventricular arrhythmias, or mortality associated with Amyl inhalation.
erectalis tablets

Table 3—Echo-Doppler Parameters in Patients with Hypertrophic Cardiomyopathy

							Doppler Peak
					S-MV	Doppler Peak	Velocity
	LVIDd,	PWTd,	SWTd,	Resting SAM,	Dist,	Resting	Following Amyl,
Group	cm	cm	cm	No. of Patients	cm	Velocity, m/s	m/s
Resting obstruction	2.9±0.5t	1.8±0.5t	2.4±0.32t	61t	1.9±0.6f	4.2±1.3t
(n = 63)	(1.7-3.6)	(1.3-2.6)	(1.4-3.0)		(0.9-3.2)	(2.2-8.0)
Latent obstruction	3.7±0.7	1.3 ±0.3$	2.0 ±0.2$	13$	2.3 ±0.6$	1.8±0.2	4.5 ±1.2$
(n = 25)	(1.9-4.6)	(1.0-1.8)	(1.4-2.3)		(1.4-3.3)	(1.4-2.1)	(2.9-7.0)
No obstruction	3.9 ±0.6	1.6±0.3	1.8±0.3	4	2.7±0.7	1.7±0.3	2.2±0.3
(n = 22)	(2.1-4.9)	(1.1-2.1)	(1.4-2.4)		(1.8-4.3)	(1.1-2.0)	(1.5-2.6)
Amyl not given	3.9 ±0.6	1.5±0.4	1.8±0.3	12	2.8 ±0.5	1.8±0.4
(n = 35)	(2.1-5.2)	(1.1-2.1)	(1.4-2.3)		(2.0-4.3)	(1.2-2.1)