Prevalenza di sesso
TABELLA II: MISURAZIONI PARAMETRI N°
ordine crescente di aggravamento del valore della scala (da B a D).
Il numero del caso clinico corrisponde a quello riportato nella tabella I (segnalamento).
TABELLA II: MISURAZIONI PARAMETRI N°
caso
SF EF La/Ao Vsx_dia_ EDVI Vsx_sis_ ESVI ACVIM P (sec) 1 37% 67% 1,3 4,02 72,64 2,53 23,58 B1 0,05 2 38% 70% 1,4 2,83 40,76 1,54 8,72 B1 0,04 3 45% 79% 1,5 2,41 74 1,32 15,72 B1 0,04 4 47% 80% 1,4 2,97 81,18 1,57 16,22 B1 0,04 5 37% 68% 1,2 4,04 73,5 1,53 6,54 B1 0,04 6 32% 62% 1,1 2,99 56,51 2,03 21,52 B1 0,04 7 43% 76% 1,2 2,81 38,78 1,59 9,17 B1 0,04 8 37% 67% 1,5 4,34 81,7 2,75 27,2 B1 0,04 9 26% 52% 1,3 3,46 57,3 2,57 27,69 B1 0,04 10 30% 60% 1,1 2,48 37,29 1,74 15,18 B1 0,04 11 36% 69% 1,4 2,03 39,64 1,3 12,46 B1 0,04 12 31% 61% 1,1 2,48 28,46 1,71 11,08 B1 0,04 13 45% 79% 1,3 2,23 35,76 1,23 7,65 B1 0,04 14 39% 70% 1,4 4,14 64,29 2,51 19,08 B1 0,04 15 44% 78% 1,3 2,22 56,13 1,25 12,68 B1 0,04 16 32% 62% 1,3 2,97 53,25 2,02 20,35 B1 0,04 17 39% 71% 1 2,73 68,72 1,67 19,83 B1 0,04 18 44% 78% 1,1 1,98 43,78 1,12 9,86 B1 0,04 19 39% 72% 1,2 2,67 72,49 1,67 22,1 B1 0,04 20 33% 65% 1,3 1,78 44,96 1,19 15,64 B1 0,04 21 51% 85% 1 1,77 44,31 0,87 6,71 B1 0,04 22 34% 67% 1,5 1,68 29,55 1,11 9,91 B1 0,04 23 59% 89% 1,3 3,82 74,65 1,56 7,99 B1 0,04 24 30% 60% 1,3 2,64 36,84 1,85 15,03 B1 0,04 25 39% 70% 1,6 3,59 77,94 2,2 23,36 B1 0,04 26 40% 72% 1,7 3,12 51,75 1,87 14,41 B1 0,04 27 62% 92% 1 2,45 52,54 0,93 4,19 B1 0,04 28 30% 59% 1,25 2,84 65,27 1,92 24,46 B1 0,04
29 43% 73% 1,3 2,26 71,77 1,29 16,85 B1 0,04 30 32% 63% 1,3 2,5 76,61 1,69 28,35 B1 0,04 31 49% 82% 1,5 2,77 60,98 1,4 10,71 B1 0,04 32 44% 75% 1,2 2,4 59,02 3,01 33,29 B1 0,04 33 45% 70% 1,5 1,73 50,44 3,07 44,06 B1 0,04 34 55% 87% 1,5 3,14 45,91 1,41 6,05 B1 0,04 35 34% 63% 1,4 2,56 24,28 3,06 37,67 B1 0,04 36 33% 63% 1 3,31 56,06 2,2 20,43 B1 0,04 37 30% 57% 1,3 2,68 35,64 1,62 9,95 B1 0,06 38 48% 74% 1,4 3,94 69,25 2,26 17,78 B1 0,04 39 33% 63% 1,1 2,64 58,48 1,78 21,61 B1 0,04 40 35% 65% 1,4 3,8 63,53 2,48 22,44 B1 0,04 41 41% 73% 1,1 3,15 52,97 1,87 14,41 B1 0,04 42 44% 78% 1,2 1,56 22,72 8,8 1442,2 B1 0,04 43 38% 71% 1,1 2,2 54,87 1,35 15,55 B1 0,06 44 48% 78% 1,3 2,52 56,36 1,44 13,47 B1 0,04 45 30% 59% 1,3 2,77 71,23 1,94 29,15 B1 0,04 46 45% 78% 1,3 3,64 53,79 1,99 12,09 B1 0,04 47 27% 53% 1,24 4 61,32 2,94 29,18 B1 0,04 48 42% 75% 1,4 2,28 53,16 1,32 12,98 B1 0,04 49 33% 64% 1,26 2,81 50,81 1,87 18,27 B1 0,04 50 41% 75% 1,26 2,21 30,96 1,3 7,85 B1 0,04 51 41% 74% 1,5 2,48 46,67 1,47 12,26 B1 0,04 52 45% 79% 1,23 2,18 53,62 1,2 11,38 B1 0,04 53 34% 64% 1,2 3,76 81,17 2,48 29,4 B1 0,04 54 32% 61% 1,87 1,15 32,2 3,79 66,1 B1 0,04 55 29% 59% 1,28 2,5 51,08 1,76 20,99 B1 0,04 56 46% 79% 2 2,74 69,34 1,48 14,48 B1 0,04 57 45% 78% 1,35 2,72 39,66 3,12 55,52 B1 0,04 58 30% 57% 1 4,08 89,82 2,87 38,44 B1 0,04 59 40% 72% 1,2 6,13 26,56 1,88 15,27 B1 0,04 60 29% 56% 1,2 4,04 73,5 2,88 32,48 B1 0,04 61 46% 78% 1,2 3,64 64,73 1,98 14,37 B1 0,04 62 30% 60% 1,4 2,51 61 1,75 24,46 B1 0,04 63 40% 71% 1,4 3,7 49,7 2,23 14,34 B1 0,04 64 34% 63% 1,4 3,3 51,11 2,4 23,35 B1 0,03 65 37% 67% 1,5 4,63 128,55 2,77 37,43 B2 0,06 66 33% 63% 1,6 2,94 87,65 1,85 27,44 B2 0,04 67 35% 65% 1,8 4,01 94,62 2,72 36,97 B2 0,04
68 34% 63% 1,6 3,43 80,68 2,28 29,52 B2 0,04 69 40% 70% 1,6 1,34 80,98 1,41 31,71 B2 0,04 70 45% 78% 1,6 2,67 78,8 1,47 17,23 B2 0,04 71 32% 64% 1,8 1,81 140,76 1,23 50,37 B2 0,04 72 45% 65% 1,6 2,67 93,92 1,77 19,1 B2 0,04 73 36% 65% 1,6 4,63 108,72 2,98 37,88 B2 0,05 74 45% 78% 1,8 3,36 114,11 18,5 52,49 B2 0,04 75 52% 85% 1,4 1,6 86,53 8,3 36,2 B2 0,06 76 37% 67% 1,7 3,78 80,84 2,4 23,35 B2 0,04 77 42% 74% 1,7 4,28 94,14 2,52 26,09 B2 0,04 78 28% 55% 1,6 3,17 80,14 2,29 35,88 B2 0,04 79 29% 56% 1,6 3,89 88,03 2,77 38,67 B2 0,04 80 41% 72% 1,5 4,26 82,45 2,52 20,3 B2 0,04 81 40% 72% 1,7 4,01 101,51 2,39 28,76 B2 0,04 82 42% 73% 1,7 4,37 83,04 2,53 22,13 B2 0,04 83 50% 83% 1,9 2,8 83,15 1,53 31,79 B2 0,05 84 49% 82% 1,7 2,83 82,08 1,44 34,73 B2 0,04 85 46% 80% 1,6 3,42 124,32 1,82 25,84 B2 0,04 86 53% 84% 2 4,24 96,28 1,98 38,32 B2 0,04 87 58% 89% 1,6 3,31 118,05 1,38 12,92 B2 0,04 88 28% 56% 1,4 2,25 64,72 2,98 49,64 B2 0,04 89 45% 77% 1,8 3,46 82,39 1,91 18,84 B2 0,04 90 44% 76% 1,6 3,32 78,59 1,8 17,06 B2 0,04 91 46% 76% 1,7 3,69 97,97 2,03 22,42 B2 0,04 92 46% 78% 1,6 4,35 123,05 2,33 26,99 B2 0,04 93 50% 83% 1,6 29,4 83,12 14,7 19,32 B2 0,04 94 54% 87% 2 2,92 99,88 1,33 9,42 B2 0,04 95 76% 42% 1,7 1,19 90,34 1,33 12,55 B2 0,04 96 40% 72% 1,7 3,44 73,07 2,07 20,8 B2 0,04 97 49% 81% 1,75 3,84 113,75 1,96 21,65 B2 0,04 98 22% 45% 1,6 3,51 117,21 2,74 64,11 B2 0,04 99 44% 76% 1,6 3,07 81,73 1,73 19,37 B2 0,04 100 43% 74% 1,6 4,04 82,78 2,31 16,05 B2 0,04 101 39% 72% 1,6 3,55 116,18 2,5 49,27 B2 0,04 102 41% 73% 2 2,93 89,38 1,73 23,74 B2 0,04 103 82% 51% 1,6 4,02 106,08 2,07 21,8 B2 0,04 104 58% 88% 2,1 3,5 86,17 2,2 21,08 B2 0,04 105 40% 79% 1,62 2,4 87,31 1,44 15,47 B2 0,04 106 42% 74% 1,4 2,9 109,07 1,69 27,97 B2 0,04
107 40% 71% 1,7 3,49 87,89 2,17 21,03 B2 0,04 108 42% 72% 1,7 3,25 87,15 2,1 19,36 B2 0,04 109 36% 68% 2 2,16 86,78 1,88 25,83 B2 0,04 110 57% 88% 2 3,9 85,73 2 16,56 B2 0,04 111 37% 69% 1,8 2,52 80,26 1,59 12,47 B2 0,04 112 61% 92% 2 2,09 84,53 0,82 6,28 B2 0,04 113 41% 73% 1,6 3,19 86,71 1,88 23,18 B2 0,04 114 31% 59% 1,7 3,89 80,2 2,69 32,77 B2 0,04 115 52% 85% 2 2,5 82,31 1,21 12,67 B2 0,04 116 51% 83% 1,9 3,6 163,22 1,76 47,51 C 0,05 117 38% 69% 1,8 3,4 129,58 2,11 39,83 C 0,04 118 48% 79% 2,2 4,6 207,63 2,4 43 C 0,04 119 43% 74% 2 4,58 168,25 2,63 44,21 C 0,04 120 22% 44% 1,9 4,41 111,17 3,45 61,96 C 0,04 121 38% 67% 2 6,03 280,4 3,73 91,27 C 0,09 122 46% 78% 2 3,33 107,24 1,8 23,11 C 0,04 123 52% 84% 2 3,5 93,33 1,68 41,73 C 0,05 124 34% 63% 3 4,44 162,08 2,93 59,77 C 0,06 125 66% 94% 2,3 2,66 102,31 0,9 46,08 C 0,05 126 55% 87% 2 3,44 146,31 1,54 19,46 C 0,05 127 88% 57% 2 3,2 87,37 2 27,15 C 0,04 128 35% 64% 1,7 4,62 113,87 30 67,55 C 0,04 129 51% 51% 2,5 3,66 84,81 2,74 41,95 C 0,04 130 23% 45% 1,8 5,62 179,41 4,33 97,78 C 0,04 131 40% 72% 3 3,61 125,39 2,15 34,99 C 0,09 132 40% 71% 2 4,55 169,9 2,73 49,72 C 0,04 133 19% 39% 1,7 6,41 205,56 5,18 126,08 C 0,09 134 38% 68% 2,5 4,7 104,97 2,94 54,16 C 0,09 135 54% 85% 2,5 5,57 175,76 2,54 26,89 C 0,09 136 44% 76% 1,9 3,73 140,87 2,1 54,25 C 0,04 137 57% 88% 3 3,82 155,28 1,63 48,62 C 0,07 138 62% 92% 2 3,33 119,78 1,25 9,95 C 0,04 139 30% 57% 2,2 5,16 160,42 3,61 69,1 C 0,04 140 37% 69% 2 3,6 229,44 2,4 84,98 C 0,04 141 33% 60% 1,9 6,4 196,72 4,8 101,43 C 0,04 142 81% 47% 2,3 2,5 47,61 1,32 9,23 C 0,04 143 29% 55% 1,8 5,23 151,98 3,71 67,75 C 0,04 144 35% 64% 2,5 5,41 164,35 1,44 6,3 C 0,04 145 55% 87% 2,5 2,42 107,78 1,1 13,94 C 0,04
146 61% 92% 2 1,82 92,37 7,2 53 C 0,04 147 46% 79% 2 3,8 136,75 1,8 21,46 C 0,04 148 26% 50% 1,8 5,42 140 4,09 23,74 C 0,04 149 34% 69% 2,5 3,33 111,66 2,07 34,38 C 0,09 150 35% 62% 1,7 5,01 193,38 2,9 52,44 C 0,08 151 44% 77% 1,8 2,45 108,38 1,36 23,91 C 0,04 152 41% 71% 1,8 5,28 194,85 3,12 55,94 C 0,06 153 54% 85% 2,3 5,24 191,45 2,4 29,28 C 0,04 154 20% 40% 2 8,28 331,76 6,32 180,69 D 0,04 155 53% 27% 3 5,63 224,25 4,09 106,38 D 0,09
TABELLA III
Parametri Descrizione
SF
Frazione di accorciamento: esprime la percentuale di riduzione del diametro ventricolare in sistole (il valore ottenuto è abbastanza variabile nelle diverse razze canine, tende a essere più elevato nei cani di razza piccola , mentre nelle razze grandi si possono trovare soggetti normali con frazioni di accorciamento più basse del 35%).
EF
Frazione di eiezione: va interpretato come indicatore della risposta contrattile. Tale valore è influenzato da numerosi fattori, quali il carico diastolico, il carico sistolico, i trattamenti farmacologici e la contrattilità intrinseca.
La/Ao
Rapporto atrio sinistro/aorta.
Consente di confrontare il diametro atriale, in progressivo aumento in numerose cardiopatie, e l’anulus aortico, che è invece relativamente stabile. I valori di riferimento per la normalità sono inferiori a 1,5 e 1,7 a seconda della taglia dell’animale.
Vsx_dia_ Diametro diastolico ventricolo sinistro. EDVI
Indice di volume telediastolico espresso in mL/m² (calcolo eseguito con la formula di Teicholz). Indipendentemente dalla taglia, i valori di riferimento per la normalità sono compresi fra 80 e 100 mL/m².
Vsx_sis_ Diametro sistolico ventricolo sinistro. ESVI
Indice di volume telesistolico espresso in mL/m²(calcolo eseguito con la formula di Teicholz). Indipendentemente dalla taglia, il valore di riferimento per la normalità deve essere uguale o inferiore a 30 mL/m².
P (sec)
Durata in secondi sul piano delle ascisse della deflessione elettrocardiografica P.
3.4 DISCUSSIONE
Per non rendere troppo pesante la lettura della tesi sono stati riportati come esempio solo i grafici che riguardano la correlazione della durata dell’onda P (sempre sull’asse delle ordinate) e i valori di La/Ao, EDVI ed ESVI su quello delle ascisse.
GRAFICO 1
Sample size Correlation
coefficient r Significance level
95% Confidence interval for r Coefficient of determination R2 155 0,7962 P<0,0001 0,7302 to 0,8475 0,6340 y = 0,0005838 + 0,02939 x
GRAFICO 2
Sample size Correlation
coefficient r Significance level
95% Confidence interval for r Coefficient of determination R2 155 0,7252 P<0,0001 0,6408 to 0,7922 0,5259 y = 0,02759 + 0,0002412 x
GRAFICO 3
Sample size Correlation
coefficient r Significance level
95% Confidence interval for r Coefficient of determination R2 155 0,5701 P<0,0001 0,4532 to 0,6677 0,3250 y = 0,03767 + 0,0004102 x
3.5 CONCLUSIONI
Lo studio condotto ha messo in evidenza che la sensibilità dell’elettrocardiogramma per il rilevamento di ingrandimenti camerali atriali in pazienti affetti da endocardiosi mitralica e per il monitoraggio della patologia stessa è inferiore a quella dell’ecocardiografo.
In particolare, l’elettrocardiogramma ha dimostrato una buona specificità nel diagnosticare ingrandimento atriale nei soggetti che versano nei più gravi stati della malattia mitralica (soggetti C e D della scala ACVIM).
Soprattutto in questi soggetti, ma in generale in quelli che hanno un rapporto La/Ao superiore a 2, la durata dell’onda P risulta aumentata.
Per quanto riguarda invece i soggetti B1 e B2, non si è notata una buona correlazione fra i valori ecocardiografici e quelli elettrocardiografici, con la conclusione che per i pazienti affetti da una endocardiosi mitralica ai primi stadi di sviluppo l’ECG non può essere considerato uno strumento diagnostico sensibile di ingrandimento atriale.
Le nostre conclusioni sono in linea a quelle dello studio effettuato nel 2012 da Borgarelli 111, anche se nella nostra indagine è stata messa in evidenza una
buona correlazione fra i valori della durata dell’onda P e i valori ottenuti con le scansioni ecocardiografiche dei soggetti più gravi.
C’è da dire che lo studio condotto presenta alcune limitazioni, prima fra tutte il numero dei soggetti presi in considerazione; 155 pazienti non possono essere infatti considerati rappresentativi dell’intera popolazione canina.
Inoltre, i valori recuperati sono stati ottenuti da misurazioni eseguite da operatori diversi e con diversi macchinari, in particolare riguardo all’ecocardiografia; questo ha sicuramente inciso sulla variabilità dei dati presi in considerazione.
Per i valori elettrocardiografici bisogna considerare che vi è una percentuale di casistica in cui alterazioni del tracciato (sia fisiologiche che patologiche) quali wandering-pacemaker, artefatti (in particolar modo dovuti a tremori muscolari e talvolta a scarsa collaborazione dei pazienti) e disturbi elettrici intermittenti interatriali possono aver falsato alcune misurazioni.
Del resto anche il rilevamento di onde P con voltaggio aumentato può spesso essere dovuto a fenomeni di tachicardia, e quindi non deve essere necessariamente considerato diagnostico di ingrandimento atriale destro.
Si precisa però che le misurazioni sono state eseguite considerando non una sola deflessione elettrocardiografica dell’onda P nel tracciato, ma analizzando perlomeno 6 deflessioni P successive corrispondenti a 6 battiti cardiaci (come indicato dalla letteratura) 67,81. In questo modo si è cercato di ridurre il rischio si
sovrastimare o sottostimare la lunghezza dell’onda P.
Concludendo l’esame ECG risulta un buon ausilio nella pratica clinica ambulatoriale per valutare le alterazioni elettriche a livello del muscolo cardiaco e gli squilibri di ordine elettrolitico, oltre a rivelarsi una metodica specifica per valutare ingrandimenti importanti delle camere cardiache.
BIBLIOGRAFIA
1. ABHAYARATNA WP et al: “Left atrial size. Phisiologic determinants and clinical applications” in Journal of the American College of Cardiology, December 2006, vol. 47, n° 12, pagg. 2357 – 2363.
2. ALPERT MA et al: “Electrocardiographic diagnosis of left atrial enlargement” in Archives of Internal Medicine, July 1989, vol. 149, pagg. 1161 – 1170.
3. ANGELINI A et al: “Anatomy of mitral valve” in BOUDOULAS H & WOOLEY CF eds. Mitral Valve: Floppy Mitral Valve, Mitral Valve Prolapse and Mitral Valvular Regurgitation, 2nd revised, Armonk Inc., New York, 2000, pagg. 5 – 29.
4. AREVALO AC et al: “A simple electrocardiographic indication of left atrial enlargement” in Journal of the American Medical Association, March 1963, vol. 185, pagg. 358 – 363.
5. ARIYARAJAH V et al: “Correlation of left atrial size with P-wave duration in interatrial block” in Chest Journal, September 2005, vol. 128, pagg. 2615 – 2621.
6. AKTINS C et al: “Guideline for the diagnosis and treatment of canine chronic valvular heart disease” in Journal of Veterinary Internal Medicine, February 2009, col. 23, pagg. 1142 – 1150.
7. AVIERINOS JF et al: “Natural history of asymptomatic mitral valve prolapse in the community” in Circulation, October 2002, vol. 106, pagg. 1355 – 1361.
8. BERGMAN KS et al: “Effect of body position on the diagnostic accuracy of the electrocardiogram” in American Heart Journal, February 1989, vol. 117, pagg. 204 – 213.
9. BIGG PW et al: “Pathogenesis of mitral valve disease in mucopolysaccharidosis
VII dogs” in Molecular Genetics and Metabolism, April 2013, vol. 110, pagg. 319-328 .
10. BIRKBECK JP et al: “P-wave morphology correlation with left atrial volumes assessed by 2-dimensional echocardiography” in Journal of Electrocardiology, January 2006, vol. 39, pagg. 225 – 229.
11. BIZZETI M & SGORBINI M: Manuale di Semeiotica Medica Veterinaria, Facoltà di Medicina Veterinaria – SEU – Pisa, 2012.
12. BLUME GG et al: “Left atrial function: physiology, assessment, and clinical implications” in European Journal of Echocardiography, May 2011, vol. 12, pagg. 421 – 430.
13. BOB JA et al: “Intraindividual variability in electrocardiograms” in Journal of Electrocardiology, May 2008, vol. 41, pagg. 190 – 196.
14. BORGARELLI M : Mitral valve insufficiency in large breed dogs [PhD thesis], Grugliasco, Italy, Dept of Patologia Animale, University of Turin, 2004.
15. BORGARELLI M et al: “Comparaison of primary mitral valve disease in German Shepherd dogs and in small breeds” in Journal of Veterinary Cardiology, January 2004, vol. 6, pagg. 25 – 31.
16. BORGARELLI M et al: “Decreased systolic function and inadequate hypertrophy in large and small breed dogs with chronic mitral valve insufficiency” in Journal of Veterinay Internal Medicine, January 2007, vol. 21, pagg. 61 – 67.
17. BORGARELLI M et al: “Survival characteristic and prognostic variables of dogs with mitral regurgitation attributable to myxomatous valve disease” in Journal Veterinary Internal Medicine, April 2008, vol. 22, pagg. 120 – 128.
18. BORGARELLI M et al: “Canine degenerative myxomatous mitral valve disease: natural history, clinical presentation and therapy” in Veterinary Clinic Small Animals, July 2010, vol. 40, pagg. 651 – 663.
19. BORGARELLI M et al: “Anatomic, histologic, and two-dimensional echocardiographic evaluation of mitral valve anatomy in dogs” in American Journal of Veterinary Research, March 2011, vol. 72, pagg. 1186 – 1192.
20. BOSWOOD A et al: “The diagnostic accuracy of different natriuretic peptides in the investigation of canine cardiac disease” in Journal of Small Animal Practise, January 2008, vol. 49, pagg. 26 – 32.
21. BOSWOOD A: “Veterinary cardiology: a journey through time” in Veterinary Record, June 2013, vol. 172, pagg. 678 – 682.
22. BOUZAS-MOSQUERA A et al: “Left atrial size and risk for all-cause mortality and ischemic stroke” in Journal of Canadian Medical Association, July 2011, vol. 183, n° 10, pagg. 657 – 664.
23. BUPP JE et al: “Placement of cardiac electrodes: written, simulated, and actual accuracy” in American Journal of Critical Care, June 1997, vol 6, pagg. 457 – 465.
24. CASACLANG – VERZOSA G et al: “Structural and functional remodeling of the left atrium: clinical and therapeutic implications for atrial fibrillation” in Journal of America College of Cardiology, January 2008, vol. 51, pagg. 1 – 11.
25. CHEN CY et al: “Normal limits of the electrocardiogram in a Chinese population” in Journal of Electrocardiology, January 1994, vol. 22, pagg. 1 – 15.
26. CHEN SC et al: “Echocardiographic parameters are independently associated with rate of renal function decline and progression to dialysis in patiens with chronic Kidney disease” in Clinical Journal of American Society of Nephrology, June 2011, vol. 6, pagg. 2750 – 2758.
27. CHIRIFE R et al: “Electrocardiographic detection of left atrial enlargement. Correlation of P wave with left atrial dimension by echocardiography” in British Heart Journal, November 1975, vol. 37, pagg. 1281 – 1285.
28. CHOONG C et al: “Combined influence of ventricular loading and relaxation on the transmitral flow velocity profile in dogs measured by Doppler echocardiography” in Circulation, October 1988, vo. 78, pagg. 672 – 683.
29. CROSARA S et al: “Holter monitoring in 36 dogs with myxomatous mitral valve disease” in Australian Vetrinary Journal, October 2010, vol 88, n° 10, pagg. 386 – 392.
30. CULSHAW GJ et al: “Evaluation of innervation of the mitral valves and the effects of myxomatous degeneration in dogs” in American Journal of Veterinary Research, August 2010, vol. 71, pagg. 194 – 202.
31. CUNNINGHAM JG: Manuale di fisiologia veterinaria, trad. it. a cura di L. AVALLONE et al, presentazione di S. NAITANA, Antonio Delfino editore, Roma, 2006.
32. DE FRANCESCO TC: “Management of cardiac emergencies in small animals”, in Veterinary Clinics Small Animal, September 2013, vol. 43, pagg. 817 – 842.
33. DE MARIA AN et al: “Arrhythmias in the mitral valve prolapse sindrome” in Annals of Internal Medicine March 1976, vol. 84, pagg. 656 – 660.
34. DIERY A et al: “Automated ECG diagnostic P-wave analysis using wavelets” in Computers Methods and Programs in Biomedicine, January 2011, vol. 101 pagg. 33 – 43.
35. DILAVERIS P et al: “Effects of ischemia on P wave dispersion and maximum P wave duration during spontaneous angina episodes” in Pacing and Clinical Electrophysiology (PACE), March 1999, vol. 22, pagg. 1640 – 1647.
36. DILAVERIS P et al: “P wave dispersion: a novel predictor of paroxysmal AF” in Annals of Noninvasive Electrocardiology (ANE), July 2001, vol. 6, pagg. 159 – 165.
37. DILAVERIS P et al: “Current morphologic and vectorial aspects of P-wave analysis” in Journal of Electrocardiology, October 2009, n° 42, pagg. 395 – 399.
38. DINES DE & PARKIN TW: “Some observation on the P wave morphology in precordial lead V-1 in patiens with elevated left atrial pressures and left atrial enlargement” Proceedings Mayo Clinic, March 1959, vol. 34, pagg. 401 – 413.
39. DIXEN U et al: “Signal-aver-aged P wave duration and the dimensions of the atria” in Annals of Noninvasive Electrocardiology, September 2004, vol. 9, pagg. 309 – 315.
40. ECKENFELS A et al: “The normal electrocardiogram of the conscious beagle dog” in Toxicology Applied Pharmacology, March 1979, vol. 47, pagg. 567 – 584.
41. EICHHORN E & GHEORGHIADE M: “Digoxin” in Progress in Cardiovascular Disease, February 2002, vol. 44, pag. 251 – 266.
42. ENRIQUEZ-SARANO M et al: “Quantitative determinants of the outcome of asymptomatic mitral regurgitation” in New England Journal of Medicine, July 2005, vol 352, pagg. 875 – 883.
43. FONTANA ME: “Mitral valve prolapse and floppy mitral valve: physical examination” in BOUDOULAS H K et al, Mitral valve: floppy mitral valve, mitral valve prolapse, mitral valve regurgitation, Armonk Inc., New York, 2000, pagg. 283 – 304.
44. FUJII Y & WAKAO Y: “Spectral analysis of heart rate variability in dogs with mild mitral regurgitation” in American Journal of Veterinary Research, January 2003, vol. 64, pagg. 145 – 148.
45. GÖRENEK B et al: “Electrocardiographic quantification of left atrial volume. A letter on the article by Ariyarajah et al entitled <<Formulaic quantification of echocardiografic left atrial volume (J. Electrocardiol., 2008 Dec. 24)>>” in Journal of Electrocardiology, March 2009, vol. 42, pagg. 424 – 425.
46. GUNDUZ H et al: “The relationship between P wave dispersion and diastolic
dysfuncntion” in Texas Heart Institute Journal, January 2005, vol. 32, pagg. 163 – 167.
47. HÄGGSTRÖM J et al: “Chronic valvular disease in the cavalier King Charles
Spaniel in Sweden” in The Veterinary Record, May 1992, vol. 131, pagg. 549 – 553.
48. HÄGGSTRÖM J et al: “New insights into degenerative mitral valve disease in
dogs” in Veterinary Clinics Small Animal Practice, April 2004, vol. 34, pagg. 1209 – 1226.
49. HÄGGSTRÖM J et al: “Acquired valvular heart disease.” in Textbook of Veterinary Internal Medicine. Diseases of Dogs and Cats, 6th edn. Eds S. Ettinger
and E Feldman, Elsevier Saunders 2005, Philadelphia, PA, USA pagg. 1022 – 1040.
50. HÄGGSTRÖM J et al: “An update on treatment and prognostic indicators in canine mixomatous mitral valve disease” in Journal of Small Animal Practice, February 2009, vol. 50 (Suppl.), pagg. 25 – 33.
51. HAMLIN RL: “Natural occurring mitral regurgitation in the dog” in BOUDOULAIS H & WOOLEY C editors, Mitral valve: floppy mitral valva prolapse, mitral valve regurgitation, 2nd edn, Armonk Inc., New York, 2000, pagg. 701 – 719.
52. HAMLIN RL: “Geriatric heart diseases in dogs” in Veterinary Clinics Small Animal Practice, May 2005, vol. 35, pagg. 597 – 615.
53. HANSSON K et al: “Left atrial to aortic root indices using two-dimensional and M-mode echocardiography in Cavalier King Spaniels with and without left atrial enlargement” in Veterinary Radiology & Ultrasound, June 2002, vol. 43, pagg. 568 – 575.
54. HAYECK E et al: “Mitral valve prolapse” in Lancet, July 2005, vol. 365, pagg. 507 – 518.
55. HAZEN MS et al: “Diagnostic accuracy of the resting electrocardiogram in detection and estimation of left atrial enlargement: an echocardiographic correlation in 551 patiens” in The American Heart Journal, March 1991, vol. 122, pagg. 823 – 828.
56. HENRY WL et al: “Relation between echocardiographically dedermined left
atrial size and atrial fibrillation” in Circulation, July 1976, vol. 53, pagg. 273 – 281.
57. HO-MING SU et al: “P wave dispersion and maximum P wave duration are indipendently associated with rapid renal function decline” in Plos / one, August 2012, vol 7, Issue 8, pagg. 1- 7.
58. HOPKINS CB & BARRET Jr O: “Electrocardiographic diagnosis of the left atrial enlargement. Role of the P terminal force in lead V1” in Journal of Electrocardiology, March 1989, vol. 22, pagg. 359 – 362.
59. IKRAM H et al: “The non-invasive recognition of left atrial enlargement: comparison of electro-and echocardiographics measurements” in Postgraduate Medical Journal, July 1977, vol. 53, pagg. 356 – 359.
60. JOLDA-MYDLOWSKA B et al: “Estimation of the P wave and PQ interval dispersion in patients with the recent myocardial infarction” in Polski Merkuriusz Lekarski, March 2005, vol. 18, pagg. 499 – 502.
61. JOSEPHSON ME et al: “Electrocardiographic left atrial enlargement. Electrophysiologic, echocardiographic, and hemodynamic correlates” in American Journal of Cardiology, April 1977, vol. 39, pagg. 967 – 975.
62. KHAN NA et al: “Kidney function and mortality among patiens with left ventricular systolic dysfunction” in Journal of American Society of Nephrology, February 2006, vol. 17, pagg. 244 – 253.
63. KHOO CW et al: “Assessment of left atrial volume: a focus on echocardiographic methods and clinical implications” in Clinical Research in Cardiology, February 2011, vol. 100, pagg. 97 – 105.
64. KITTLESON MD & KIENLE RD: Small Animal Cardiovascular Medicine, Mosby, Inc. St. Louis MO, USA, 1998.
65. KITTLESON MD & BROWN W: “Regurgitant Fraction measured by using the proximal isovelocity surface area in dogs with chronic myxomatous mitral valve disease” in Journal of Veterinary Internal Medicine, January 2003, vol. 17, pagg. 84 – 88.
66. KLIGFIELD P et al: “Arrhithmias and sudden death in mitral valve prolapse” in American Heart Journal, March 1987, vol. 113, pagg. 1298 – 1307.
67. KLIGFIELD P et al: “Recommendations for the standardization and interpretation od the electrocardiogram: part I: the electrocardiogram and its technology”, in Journal of American College of Cardiology, September 2007, vol. 49, pagg. 1109 – 1121.
68. KOSAR F et al: “P-wave duration and dispersion in obese subjects” in Annals of Noninvasive Electrocardiology, January 2008, vol. 13, n° 1, pagg. 3 – 7.
69. KRAUS MS et al: “Morphology of ventricular arrhythmias in the boxer as measured by 12-lead electrocardiography with pace-mapping et al, comparaison” in Journal of Veterinary Internal Medicine, July 2002, vol. 16, pagg. 153 – 158.
70. KUHN L et al: “ECG interpretation part 1: understanding mean electrical axis”
in Journal of Emergency Nursing, December 2008, vol. 34, n° 6, pagg. 530 – 534.
71. LEE KS et al: “Relation of electrocardiographic criteria for left atrial enlargement to two-dimensional echocardiographic left atrial volume measurements” in The American Journal of Cardiology, November 2007, n° 99, pagg. 113 – 118.
72. LESTER SJ et al: “Best method in clinical practice and research studies to determine left atrial size” in American Journal of Cardiology, June 1999, vol. 84, pagg. 829 – 835.
73. LEWIS T et al: “Heritability of premature mitral valve disease in Cavalier King
Charles Spaniel” in Veterinary Journal, May 2011, vol. 188 (1), pagg. 73 – 76.
74. LO HM et al: “Characteristic p wave morphology in patiens undergoing the atrial compartment operation for chronic atrial fibrillation with mitral valve disease” in Pacing and Clinical Electrophysiology (PACE), September 2003, vol. 26, pagg. 1864 – 1872.
75. LOMBARD CW & SPENCER CP: “Correlation of radiographic, ecocardiographic, and electrocardiographic signs of left heart enlargement in dogs
with mitral regurgitation” in Veterinary Radiology, April 1985, vol. 26, pagg. 89-97.
76. MACRUZ R et al: “A method for electrocardiographic recognition of atrial enlargement” in Circulation, December 1958, vol 17, pagg. 882 – 889.
77. MACFARLANE PW & LAWRIE TDV: “Normal limits” in AA.VV., Comprehensive electrocardiology, vol. 3, Macfarlane PW & Lawrie TDV, editors, New York, 1989, pag. 1442 e sgg.
78. MARCATO PS: Patologia sistematica veterinaria, Edagricole, Milano 2008.
79. MITCHELL JH et al: “Atrial function and the hemodynamic consequences of atrial fibrillation in man.” In American Journal of Cardiology, April 1969, vol. 23, pagg. 556 – 567.
80. MOONARMART M: “Studies on the natural history and progression of acquired mitral valve insufficiency in the dog”. Thesis Royal Veterinary College, London University, UK, 2008.
81. MURPHY ML et al: “Left atrial abnormality as an electrocardiographic criterion for the diagnosis of left ventricular hypertrophy in the presence of right bundle branch block” in American Journal of Cardiology, April 1983, vol. 52, pagg. 381 – 383.
82. NAKADA Y et al: “The influence of recording postures on electrocardiogram measurements in dogs” in Advances in Animal Cardiology, October 1988, vol.21, pagg. 36 – 41.
83. NOSZCZYK-NOWAK A et al: “Comparaison of P-wave dispersion in healthy dogs, dogs with cronic valvular disease and dogs with disturbances of sopraventricular conduction” in Acta Veterinaria Scandinavica, January 2011, vol. 53:18, pagg. 1 – 6.
84. OBAYASHI K et al: “Effects of transforming growth factor-β3 and matrix- metalloproteinasi-3 on the pathogenesis of chronic mitral valvular disease in dogs” in American Journal of Veterinary Research, October 2011, vol. 72, pagg. 194 – 202.
85. O’ GRADY M et al: “Electrocardiographic evaluation of chamber enlargement” in Diagnostic electrocardiography, March 1992, vol. 33, pagg. 195 – 200.
86. OLSEN L et al: “Epidemiology and inheritance of mitral valve prolapse in Dachshunds” in Journal of Veterinary Internal Medicine, April 1999, vol. 13, pagg. 448 – 456.
87. OLSEN L et al: “Early echocardiographic predictors of myxomatous mitral valve disease in Dachshunds” in The Veterinary Record, February 2003, vol. 152, pagg. 293 – 297.
88. OZER N et al: “P wave dispersion in hypertensive patients with paroxysmal atrial fibrillation” in Pacing and Clinical Electrophysiology (PACE) June 2000, vol. 23, pagg. 1859 – 1862.
89. PAHLOW B et al: “Electrocardiographic criteria of left atrial enlargement: do they correlate with atrial size ?” in JAOA — The Journal of the American Osteopathic Association, December 1989, vol. 89, n° 12.pagg. 1 – 4.
90. PAT B et al: “Dissociation between cardiomyocyte function and remodelling with β-adrenergic receptor blockade in isolated canine mitral regurgitation” in Heart and Circulatory Physiology - American Journal of Physiology, March 2008, vol. 295, pagg. 2321 – 2327.
91. PATTERSON DF et al: “Spontaneous abnormal cardiac arrhythmias and conduction disturbances in the dog” in American Journal Veterinary Research, June 1961, vol. 22, pagg. 355 – 369.
92. PEDERSEN HD: “Effects of mild mitral valve insufficiency, sodium intake, and place of blood sampling on the renin-angiotensin system in dogs” in Acta Vetrinaria Scandinavica, September 1996, vol. 37, pagg. 109 – 118.
93. PEDERSEN HD et al: “Echocardiographic mitral valve prolapse in Cavalier King Charles Spaniels: epidemiology and prognostic significance for regurgitation” in The Veterinary Record, March 1999, vol. 144, pagg. 315 – 320.
94. PEDERSEN HD et al: “Echocardiographic study of mitral valve prolapse in Dachsunds” in Journal of Veterinary Medicine, January 1996, vol. 43, pagg. 103 – 110.
95. PERRY G et al: “Angiotensin II receptor blockade does not improve left ventricular function and remodelling in subacute mitral regurgitation in the dog”
in Journal of American College of Cardiology, December 2002, vol. 39, pagg. 1374-1379.
96. PETER W et al: “Is electrocardiography still useful in the diagnosis of cardiac chamber hipertrophy and dilatation ?” in Cardiology Clinics, March 2006, vol. 24, pagg. 401 – 411.
97. PETERS RM: “The fractal dimension of atrial fibrillation: a new method to predict left atrial dimension from the surface electrocardiogram” in Cardiology, January 1999, pagg. 17 – 20.
98. PIPBERGER HV et al: “Correlations on the orthogonal electrocardiogram and
vectorcardiogram with constitutionals variables in 518 normal men.” In Circulation, September 1967, vol. 35, pagg. 536-551.
99. PLATONOV PG: “Atrial conduction and atrial fibrillation: what can we learn from surface ECG ?” in Cardiology Journal, December 2008, vol. 15, n° 5, pagg. 402 – 407.
100. POLI S et al: “Prediction of atrial fibrillation from surface ECG: review of