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Effects of intermittent left bundle branch block on left ventricular diastolic function: a case report
si
cARIxoLOGY ELSEVIER
International Journal of Cardiology 46 (1994) 85-88
Effects of intermittent left bundle branch block on left ventricular diastolic function: a case report Han B. Xiao, Derek G. Gibson* Cardiac
Department,
Royal
Brompton
Hospital.
Sydney Strrrt.
London
S W3 6NP.
UK
Received 6 April 1994; revision accepted 21 April 1994
Abstract We investigated systolic and diastolic left ventricular function in a patient with an echocardiographically normal left ventricle and rate dependent left bundle branch block. Abnormal activation was associated with asynchronous left ventricular wall motion and secondary changes in filling pattern. The latter were similar to those seen in severe left ventricular disease. When the activation pattern reverted to normal, all of these abnormalities regressed. This case provides further evidence that abnormal activation can, on its own, cause left ventricular diastolic as well as systolic dysfunction. Keywords:
Left bundle branch block; Intermittent Left ventricular wall motion
left bundle branch block; Diastolic
function;
Left ventricular
filling;
1. Introduction
2. Case report
Observations on patients with intermittent bundle branch block have been helpful in dissociating disturbances of left ventricular systolic function due to the abnormal activation itself from those due to associated left ventricular disease [l]. In this paper we apply the same approach to a series of disturbances of diastolic function which we have previously suggested are directly due to left bundle branch block [2].
A 49-year-old female patient was referred for exercise testing, with a history of chest pain on exertion and syncope. Resting blood pressure was 130/80 mmHg, and a cardiac physical examination was normal. A resting 12-lead electrocardiogram at a heart rate of 79 beats/min showed a normal PR-interval (180 ms) and QRS duration (85 ms), along with normal septal Q-waves (Fig. la). During exercise, at a heart rate of 100 beats/min, she developed classic complete left bundle branch block. QRS duration increased to 140 ms, the PRinterval was unchanged and septal Q-waves were absent (Fig. lb). The exercise test was terminated
* Corresponding author 0167-5273/94/$07.00 SSDI
0
0167-5273(94)02079-X
1994
Elsevier Science Ireland Ltd. All rights reserved
0b Fig 1. (a) Resting ECG showing normal PR interval. QRS duration and septal Q-wnvcs (b) ECG recorded during cxcrcise IN
ing classical
pattern of complete left bundle branch block: increased QRS duration.
abs ent R’-waves
in right chest leads (Cl and CZ). Calibration
is
show
absent srptal Q-waves In Icad I. C5 and C6 an‘
I mV/cm and paper speed IS 75 mm/s In both
H. B. Xiao. D.G. Gibson /hr. Table 1 Echocardiographic
measurements
(average
Normal conduction
LBBB pattern
RR-interval (ms) LV end diastolic dimension (cm) LV end systolic dimension (cm) Q to the onset of transverse septal motion (ms) Q to the onset of longitudinal septal motion (ms) Q to the onset of LV posterior wall motion (ms) Q to the onset of LV lateral wall motion (ms) Q to the onset of RV lateral wall motion (ms) Q to aortic opening (ms) A2 to mitral opening (ms) A2 to the onset of transmitral flow (ms)
720 5.0 4.0 85
650 5.0 4.3 50
110
170
110
150
100
175
100
100
120 100 II0
200 80 120
LBBB, left bundle branch ventricular.
block; LV, left ventricular;
,~...,....,....,....,.._.,.... _~
after 2 min 50 s, when her heart rate had reached 150 beatslmin and her blood pressure was 200195 mmHg. She did not experience any chest pain. An echocardiographic study was performed. At the time her heart rate was 92 beats/min, and an ECG showed left bundle branch block (Table 1). The left ventricular end-diastolic dimension was normal, though the shortening fraction was reduced. An early systolic-septal dip was present. On the septal long-axis M-mode echogram there was a delay in the onset of shortening, and striking post-ejection shortening of 4 mm (Fig. 2a). The left ventricular filling time, measured by pulsed Doppler, was very short (160 ms) with a single peak, occurring after the P-wave of the succeeding beat (Fig. 2b). Within 5 min, the heart rate had fallen to 82 beats/min, and ventricular activation had reverted to normal. Repeat echocardiography showed that the ventricular shortening fraction was now normal and that the tilling time had increased to 300 ms (Fig. 2d). Post-ejection shorten-
of 3 beats)
Measurement
RV, right
ECG ,....,....,....,
87
J. Cardiol. 46 (1994) 85-88
.,.
.?x.F.
PCG
..a..
_
. . , . . . . , . . . . . . . . . . . . . . . . . . . ,..
A2
-
d Fig. 2. Long axis M-mode simultaneously with ECG echogram (a) and very short post-ejection shortening is
echograms of the septum and pulsed wave Doppler traces of transmitral flow velocity were recorded and phonocardiogram (PCG). There is a striking post-ejection shortening (arrow) on the M-mode tilling time on the mitral Doppler (b) in the presence of left bundle branch block. With normal activation, no longer apparent (c) and filling pattern has reverted to normal (d). A2. aortic valve closure.
88
H. B. Xiuo,
D. G. Gibson / Int. .I. Cardiol
ing of the septal long-axis was no longer apparent (Fig. 2~). Changes in systolic function, including prolongation of pre-ejection period and generalised delay in the onset of left ventricular long-axis shortening had also regressed (Table 1).
46 ( 1994) 85-8X
cause a striking deterioration of ventricular filling. We believe it is important to distinguish the effects of abnormal ventricular activation from those of irreversible left ventricular disease. Either may severely disturb diastolic function, but the treatment of the two conditions is clearly different.
3. Discussion Acknowledgements An absent septal Q-wave, whether an isolated abnormality or with left bundle branch block, is associated with prolonged shortening of the septal long-axis beyond aortic valve closure [3]. We believe that this prolongation of left ventricular wall tension delays the start of transmitral flow. However, septal Q-wave loss has been associated with septal fibrosis [4]. Such fibrosis might increase ventricular stiffness, and so directly interfere with filling. In the present case though, left ventricular cavity size, wall motion in both transverse and longitudinal axes, and transmitral flow were all within normal limits when ventricular activation was normal, but were all disturbed with left bundle branch block. Indeed, filling time dropped by more than half, and a summation pattern appeared, usually seen at rest only in severe heart disease [5]. Although heart rate is a major factor affecting left ventricular filling time, the small fall in RR-interval with the onset of block can account for only 60 ms of the 160 ms shortening observed ]51. We conclude
that left bundle
branch
block can
We are very grateful to Dr P. Harris, The Sloane Hospital, Beckenham, Kent, UK for allowing us to report this patient under his care. HBX is supported by the Royal Brompton Hospital Special Cardiac Fund. References Bramlet DA, Morris KG, Coleman RE, Albert D. Cobb FR. Effects of rate-dependent left bundle branch block on global and regional left ventricular function. Circulation 1983: 67: 1059-1065. Xiao HB, Lee CH, Gibson DC. Effect of left bundle branch block on diastolic function in dilated cardiomyopathy. Br Heart J 1991; 66: 443-447. Xiao HB, Brecker SJ, Henein MY, Jin XY, Gibson DC. Absent septal Q-wave: an unrecognised hallmark of the effects of abnormal activation pattern on left ventricular diastolic function [abstract]. Circulation 1993; 88: I-346. Burch GE. DePasquale N. A study at autopsy of the relation of absence of the Q-wave in leads I, aVL, V, and V, to septal fibrosis. Am Heart J 1960; 60: 336-340. Ng KSK, Gibson DG. Impairment of diastolic function by shortening filling period in severe left ventricular disease. Br Heart J 1989; 62: 246-252.
cARIxoLOGY ELSEVIER
International Journal of Cardiology 46 (1994) 85-88
Effects of intermittent left bundle branch block on left ventricular diastolic function: a case report Han B. Xiao, Derek G. Gibson* Cardiac
Department,
Royal
Brompton
Hospital.
Sydney Strrrt.
London
S W3 6NP.
UK
Received 6 April 1994; revision accepted 21 April 1994
Abstract We investigated systolic and diastolic left ventricular function in a patient with an echocardiographically normal left ventricle and rate dependent left bundle branch block. Abnormal activation was associated with asynchronous left ventricular wall motion and secondary changes in filling pattern. The latter were similar to those seen in severe left ventricular disease. When the activation pattern reverted to normal, all of these abnormalities regressed. This case provides further evidence that abnormal activation can, on its own, cause left ventricular diastolic as well as systolic dysfunction. Keywords:
Left bundle branch block; Intermittent Left ventricular wall motion
left bundle branch block; Diastolic
function;
Left ventricular
filling;
1. Introduction
2. Case report
Observations on patients with intermittent bundle branch block have been helpful in dissociating disturbances of left ventricular systolic function due to the abnormal activation itself from those due to associated left ventricular disease [l]. In this paper we apply the same approach to a series of disturbances of diastolic function which we have previously suggested are directly due to left bundle branch block [2].
A 49-year-old female patient was referred for exercise testing, with a history of chest pain on exertion and syncope. Resting blood pressure was 130/80 mmHg, and a cardiac physical examination was normal. A resting 12-lead electrocardiogram at a heart rate of 79 beats/min showed a normal PR-interval (180 ms) and QRS duration (85 ms), along with normal septal Q-waves (Fig. la). During exercise, at a heart rate of 100 beats/min, she developed classic complete left bundle branch block. QRS duration increased to 140 ms, the PRinterval was unchanged and septal Q-waves were absent (Fig. lb). The exercise test was terminated
* Corresponding author 0167-5273/94/$07.00 SSDI
0
0167-5273(94)02079-X
1994
Elsevier Science Ireland Ltd. All rights reserved
0b Fig 1. (a) Resting ECG showing normal PR interval. QRS duration and septal Q-wnvcs (b) ECG recorded during cxcrcise IN
ing classical
pattern of complete left bundle branch block: increased QRS duration.
abs ent R’-waves
in right chest leads (Cl and CZ). Calibration
is
show
absent srptal Q-waves In Icad I. C5 and C6 an‘
I mV/cm and paper speed IS 75 mm/s In both
H. B. Xiao. D.G. Gibson /hr. Table 1 Echocardiographic
measurements
(average
Normal conduction
LBBB pattern
RR-interval (ms) LV end diastolic dimension (cm) LV end systolic dimension (cm) Q to the onset of transverse septal motion (ms) Q to the onset of longitudinal septal motion (ms) Q to the onset of LV posterior wall motion (ms) Q to the onset of LV lateral wall motion (ms) Q to the onset of RV lateral wall motion (ms) Q to aortic opening (ms) A2 to mitral opening (ms) A2 to the onset of transmitral flow (ms)
720 5.0 4.0 85
650 5.0 4.3 50
110
170
110
150
100
175
100
100
120 100 II0
200 80 120
LBBB, left bundle branch ventricular.
block; LV, left ventricular;
,~...,....,....,....,.._.,.... _~
after 2 min 50 s, when her heart rate had reached 150 beatslmin and her blood pressure was 200195 mmHg. She did not experience any chest pain. An echocardiographic study was performed. At the time her heart rate was 92 beats/min, and an ECG showed left bundle branch block (Table 1). The left ventricular end-diastolic dimension was normal, though the shortening fraction was reduced. An early systolic-septal dip was present. On the septal long-axis M-mode echogram there was a delay in the onset of shortening, and striking post-ejection shortening of 4 mm (Fig. 2a). The left ventricular filling time, measured by pulsed Doppler, was very short (160 ms) with a single peak, occurring after the P-wave of the succeeding beat (Fig. 2b). Within 5 min, the heart rate had fallen to 82 beats/min, and ventricular activation had reverted to normal. Repeat echocardiography showed that the ventricular shortening fraction was now normal and that the tilling time had increased to 300 ms (Fig. 2d). Post-ejection shorten-
of 3 beats)
Measurement
RV, right
ECG ,....,....,....,
87
J. Cardiol. 46 (1994) 85-88
.,.
.?x.F.
PCG
..a..
_
. . , . . . . , . . . . . . . . . . . . . . . . . . . ,..
A2
-
d Fig. 2. Long axis M-mode simultaneously with ECG echogram (a) and very short post-ejection shortening is
echograms of the septum and pulsed wave Doppler traces of transmitral flow velocity were recorded and phonocardiogram (PCG). There is a striking post-ejection shortening (arrow) on the M-mode tilling time on the mitral Doppler (b) in the presence of left bundle branch block. With normal activation, no longer apparent (c) and filling pattern has reverted to normal (d). A2. aortic valve closure.
88
H. B. Xiuo,
D. G. Gibson / Int. .I. Cardiol
ing of the septal long-axis was no longer apparent (Fig. 2~). Changes in systolic function, including prolongation of pre-ejection period and generalised delay in the onset of left ventricular long-axis shortening had also regressed (Table 1).
46 ( 1994) 85-8X
cause a striking deterioration of ventricular filling. We believe it is important to distinguish the effects of abnormal ventricular activation from those of irreversible left ventricular disease. Either may severely disturb diastolic function, but the treatment of the two conditions is clearly different.
3. Discussion Acknowledgements An absent septal Q-wave, whether an isolated abnormality or with left bundle branch block, is associated with prolonged shortening of the septal long-axis beyond aortic valve closure [3]. We believe that this prolongation of left ventricular wall tension delays the start of transmitral flow. However, septal Q-wave loss has been associated with septal fibrosis [4]. Such fibrosis might increase ventricular stiffness, and so directly interfere with filling. In the present case though, left ventricular cavity size, wall motion in both transverse and longitudinal axes, and transmitral flow were all within normal limits when ventricular activation was normal, but were all disturbed with left bundle branch block. Indeed, filling time dropped by more than half, and a summation pattern appeared, usually seen at rest only in severe heart disease [5]. Although heart rate is a major factor affecting left ventricular filling time, the small fall in RR-interval with the onset of block can account for only 60 ms of the 160 ms shortening observed ]51. We conclude
that left bundle
branch
block can
We are very grateful to Dr P. Harris, The Sloane Hospital, Beckenham, Kent, UK for allowing us to report this patient under his care. HBX is supported by the Royal Brompton Hospital Special Cardiac Fund. References Bramlet DA, Morris KG, Coleman RE, Albert D. Cobb FR. Effects of rate-dependent left bundle branch block on global and regional left ventricular function. Circulation 1983: 67: 1059-1065. Xiao HB, Lee CH, Gibson DC. Effect of left bundle branch block on diastolic function in dilated cardiomyopathy. Br Heart J 1991; 66: 443-447. Xiao HB, Brecker SJ, Henein MY, Jin XY, Gibson DC. Absent septal Q-wave: an unrecognised hallmark of the effects of abnormal activation pattern on left ventricular diastolic function [abstract]. Circulation 1993; 88: I-346. Burch GE. DePasquale N. A study at autopsy of the relation of absence of the Q-wave in leads I, aVL, V, and V, to septal fibrosis. Am Heart J 1960; 60: 336-340. Ng KSK, Gibson DG. Impairment of diastolic function by shortening filling period in severe left ventricular disease. Br Heart J 1989; 62: 246-252.